Trihydrocarbyl silyl substituted alkyl diaryl phosphine transition metal complexes and their use as homogeneous hydroformylation-aldolization catalysts

ABSTRACT

Described is a carbonylation process using novel homogeneous trihydrocarbyl silyl-substituted alkyl diaryl phosphine transition metal complexes of the general formula: 
     
         [(Ar.sub.2 PQ).sub.y SiR.sub.4 -y].sub.g (MX.sub.n).sub.s 
    
     wherein Ar is a C 6  to C 10  aromatic hydrocarbyl radical, Q is a C 1  to C 30  saturated straight chain divalent radical, R is a C 1  to C 10  hydrocarbyl, wherein Ar, Q and R, can be substituted or unsubstituted, y is 1 to 4, g times y is 1 to 6, M is a transition metal selected from the group consisting of Group VIII transition metals, X is an anion or organic ligand excluding halogen satisfying the valence and coordination sites of the metal, n is 2 to 6 and s is 1 to 3, are disclosed. These materials exhibit high thermal stability and are superior catalysts for the selective hydroformylation of olefins, particularly in the presence of excess quantities of ligand of the formula: 
     
         (Ar.sub.2 PQ)ySiR.sub.4-y 
    
     wherein Ar, Q, R, and y are as previously defined. 
     Specifically, tris-(trimethyl silyl-ethyl diphenyl phosphine) rhodium carbonyl hydride, 
     
         [(CH.sub.3).sub.3 Si-CH.sub.2 CH.sub.2 -PPh.sub.2 ].sub.3 Rh(CO)H 
    
     and tris [bis-(diphenylphosphinoethyl)dimethyl silane] rhodium carbonyl hydride, 
     
         [(CH.sub.3).sub.2 Si-CH.sub.2 CH.sub.2 -PPh.sub.2 ].sub.3 Rh(CO)H, 
    
     are selective olefin hydroformylation catalysts, particularly in the presence of excess trihydrocarbyl silyl-substituted alkyl diaryl phosphine ligand.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a division of application Ser. No. 295,193, filed Aug. 21, 1981which is a continuation-in-part application of U.S. Ser. No. 192,810filed Oct. 1, 1980, which is a Rule 60 divisional of Ser. No. 11,238filed Feb. 12, 1979 which is now U.S. Pat. No. 4,298,541, issued Nov. 3,1981.

BACKGROUND OF THE INVENTION

This invention relates to trihydrocarbyl silyl-substituted alkyl diarylphosphine transition metal complex carbonylation catalysis.

More particularly, the subject of this invention is homogeneous,selective, low pressure alpha-olefin hydroformylation withtris-(silylalkyl diaryl phosphine) rhodium carbonyl hydride complexcatalysts in the presence of excess phosphine ligand.

One aspect of the invention is the derivation of the silylalkyl diphenylphosphine ligands via the anti-Markovnikov addition of a diarylphosphine to the appropriate alkenyl silane.

Another aspect is concerned with the preparation of the transition metalcomplexes of these ligands via displacement reactions. Synthesesstarting with tris(triphenyl phosphine) rhodium carbonyl hydride anddicarbonyl acetylacetonato rhodium are specifically described.

A special aspect of the invention is concerned with the physicochemicaland catalytic properties of the novel complexes, i.e., phosphinebasicity and stereochemistry versus complex formation, equilibria andstability. The selectivity and rate of hydroformylation are correlatedwith temperature, concentration of excess ligand, carbon monoxidepartial pressure and the presence of aldolization catalyst.

Finally, a special concern of the present invention is a continuous lowpressure hydroformylation of alpha-olefins, particularly butene-1,propylene and pentenes at elevated temperatures. An exemplary feature ofsuch hydroformylation involves a continuous product flashoff operation.In this process, gaseous reactants are continuously introduced into, anda mixture of gaseous products and unreacted feed is continuously removedfrom, the solution of the present homogeneous catalyst complex.

The main objective of the present invention is to provide selectivesilyl substituted alkyl diphenyl phosphine rhodium carbonyl hydridecatalysts which are more stable, and can be used in an improvedhydroformylation process at higher temperatures, than the widely usedtriaryl phosphine rhodium carbonyl hydride catalysts.

Transition metal complexes of both triphenyl phosphine and trialkylphosphines are widely studied catalysts employed in hydroformylation,hydrogenation, etc., reactions. The monograph of Juergen Falbe, "NewSyntheses with Carbon Monoxide," Springer Verlag, N.Y., 1970, deals withthe use of these materials in reactions of carbon monoxide, particularlycarbonylations. In the realm of rhodium catalyzed hydroformylations ofalpha-olefins, catalyst systems of triaryl phosphine and other trivalentphosphorus compound rhodium complexes in the presence of excessphosphine ligand which exhibited improved selectivity to normalaldehydes (over iso aldehydes) are described by R. L. Pruett and J. A.Smith in U.S. Pat. No. 3,527,809. In that patent, it is stated as beingessential that the phosphorus ligands be of weakly basic characterpossess a half neutralization potential value at least 425, preferablyat least 500, smaller than that of N,N' diphenylguanidine. The Δ HNP isonly about 400 for simple alkyl diphenyl phosphines, which are too basicaccording to Pruett and Smith.

Morrell and Sherman in German Offenlegungschrift No. 2,802,922 discloseunsubstituted alkyl diphenyl phosphines as components of stabilizedtris-(triphenyl phosphine) rhodium carbonyl hydride plus excesstriphenyl phosphine catalyst systems for hydroformylation ofalpha-olefins with CO/H₂ to give aldehydes.

In the area of silyl substituted alkyl phosphine transition metalcomplexes, the work of Grish Chandra is of importance. British Pat. Nos.1,419,769; 1,420,982; 1,421,136 by Chandra disclose rhodium complexes ofsilyl alkyl phosphines, in each of which the rhodium had attached to ita halogen. These materials are disclosed as being useful forhydro-silylation, hydrogenation and hydroformylation. Specific examplesare given only for the preparation of silylmethyl phosphine complexesand their use in hydrosilylation.

British Pat. Nos. 1,412,257; 1,414,662 and U.S. Pat. No. 3,856,837 (allto Chandra) describe nickel, palladium and platinum complexes ofsilylalkyl phosphines and their use of hydrosilylation, hydrogenation,and polymerization. In these patents, the transition metal has attachedto it a halogen or --SCN group or --SZ wherein Z represents an alkylradical having less than 18 carbon atoms or the phenyl radical.

In G.B. Pat. No. 1,412,257 the material is identified as a bridgedbinuclear complex.

In G.B. Pat. No. 1,414,662 the nickel, palladium or platinum transitiongroup metal may have associated with it a hydrogen atom or other anionicligand (X) which may be for example, H, Cl, Br, I, --NO₂, --NO₃, --SCN,--OCOCH₃, an alkyl, aryl, alkaryl or aralkyl radical. However, materialswherein X is Br are the only ones actually prepared.

In U.S. Pat. No. 3,856,837, the nickel, palladium or platinum also haveonly halogens associated with them as anionic ligands (X).

G.B. Pat. No. 925,721 to H. Niebergall deals broadly with the additionof secondary phosphines to unsaturated silanes to providesilylhydrocarbyl phosphines. He discloses materials of the formula:##STR1## wherein R₁ and R₂ are alkyl, cycloalkyl, aryl, alkaryl,aralkyl; R₃ and R₄ are alkyl, cycloalkyl, aryl, alkaryl, aralkyl orhydrogen; A is a halo, alkoxy, hydroxy, alkyl, alkaryl, cycloalkyl, arylor aralkyl radical; Z is a hydrocarbon residue having from 1 to 10carbon atoms and is preferably a saturated straight or branched chainhydrocarbon residue (or Z is a silicon to carbon linkage). Ifphosphorous is pentavalent, y is oxygen or sulfur; if phosphorous istrivalent, y is no substituent; n is 0 to 3. This patent contains noteaching that these materials can be complexed with transition metals toyield homogeneous catalysts useful in hydroformylation reactions.

Owen and Cooper disclose the preparation of similar compounds viadisplacement reactions of chlorophosphines and silylalkyl Grignardcompounds or sodium phosphides and silylalkyl halides in British Pat.No. 1,179,242.

To obtain the vinyl triphenyl silane intermediate, vinyl trichlorosilane was reacted with phenyl magnesium bromide in an ether-THF solventmixture. The cement reactions of chloro-phosphines and silylalkylGrignard compounds or sodium phosphides and silylalkyl halides.

U.S. Pat. No. 3,067,227 to Fekete describes the preparation ofalkoxysilylalkylphosphines via the method of reacting alkoxy silanes andunsaturated phosphines.

G.B. Pat. No. 1,182,763 to Jacques and Owen also disclosesilylhydrocarbylphosphine intermediates useful in the preparation of thecomplexes of the present invention.

U.S. Pat. No. 3,726,809 and 3,832,404 to Allum et al discloseheterogeneous hydroformylation catalysts (and processes using thesecatalysts). These heterogeneous catalysts are silylhydrocarbyl phosphinetransition metal complexes, bonded to a support by the interaction of areactive group on the silicon with at least one reactive hydroxyl groupon the support which may also be silicon. See also U.S. Pat. No.3,907,852 and 4,083,803 to Oswald and Murrell.

DESCRIPTION OF THE FIGURES

FIG. 1 shows the key steps and equilibria in the phosphine rhodiumcomplex catalyzed hydroformylation of olefins.

FIG. 2 shows the ³¹ P nmr spectra of rhodium carbonyl hydride complexesformed with excess TPP (triphenylphosphine) and SEP(trimethylsilylethyldiphenylphosphine) ligands and their mixtures.

FIG. 3 illustrates by ³¹ P nmr spectra ligand exchange rates of TPP andSEP complexes at various temperatures.

FIG. 4 outlines the different methods of feed gas introduction forhydroformylation on a schematic drawing of an autoclave.

FIG. 5A and 5B indicate catalyst stability of the TPP and EP complexduring hydroformylation at 145° C. and 100° C., respectively.

FIG. 6 shows the effect of SEP ligand to rhodium ratio on the n/i ratioof the aldehyde products at 145° C. and 170° C.

FIG. 7 shows the effect of CO partial pressure of the n/i ratio ofaldehyde products at 120° C.

FIG. 8 shows the aldehyde production rate during continuous butenehydroformylation.

SUMMARY OF THE INVENTION

By this invention, there is provided a carbonylation process comprisingreacting an organic compound with CO in the presence of reaction mixturecomprising a catalyst complex of the formula:

    [(Ar.sub.2 PQ).sub.y SiR.sub.4-y ].sub.g.(MX.sub.n).sub.s

wherein Ar is a substituted or unsubstituted C₆ to C₁₀ aromatic radical,Q is a substituted or unsubstituted C₁ to C₃₀ saturated open chainalkylene radical, R is an unsubstituted or monosubstituted C₁ to C₁₀hydrocarbyl radical, M is a Group VIII transition metal selected fromthe group consisting of Co, Rh, Ir, Ru, Fe or Os, X is an anion ororganic ligand, excluding halogen, satisfying the valence andcoordination sites of the metal, y is 1 to 4, g is 1 to 6 with theproviso that g times y is 1 to 6, n is 2 to 6, and s is 1 to 3, saidsubstituents on said aromatic radicl, on said alkylene radical and onsaid hydrocarbyl radical being chemically unreactive with materials usedin, and the products of, a carbonylation reaction.

DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS

Compositions encompassed and used in the present invention process arehydrocarbylsilyl alkyl diaryl phosphine complexes of selected Group VIIItransition metals free of metal bound halogen. The scope of thecompositions is co-extensive with that described in the parent case,Ser. No. 011,238, which is now U.S. Pat. No. 4,298,541, issued Nov. 3,1981, which is hereby incorporated by reference for that purpose. Theyare represented by the formula:

    [(Ar.sub.2 PQ).sub.y SiR.sub.4-y ].sub.g.(MX.sub.n).sub.s

wherein Ar is the same or different C₆ to C₁₀ substituted or nonsubstituted aromatic hydrocarbyl radical, preferably phenyl, mono-, di-or tri- substituted phenyl, most preferably phenyl; Q is a C₁ to C₃₀saturated open chain alkylene radical, preferably a straight chainalkylene radical, more preferably a C₂ to C₁₄ unsubstituted ormonosubstituted alkylene diradical; R is the same or different C₁ to C₁₀unsubstituted hydrocarbyl or C₁ to ₆ unsubstituted hydrocarbyl radical,preferably C₁ to C₆ alkyl, C₅ and C₆ cycloalkyl, phenyl, C₁ to C₆monosubstituted alkyl, monosubstituted phenyl, more preferably C₁ to C₆alkyl or phenyl, M is a Group VIII transition metal selected from Fe,Co, Rh, Ru, Ir, Os, preferably Co, Rh, Ir, and Ru, more preferably Co,Rh, most preferably Rh; y is 1 to 4, preferably 1 or 2, most preferably1; g is 1 to 6 and g times y is 1 to 6, preferably 1 to 4, morepreferably 2 or 3, most preferably 3; X is an anion or organic liquidwhich satisfies the valence and coordination sites of the metal, withthe proviso that X cannot be halogen, preferably X is H, CO and tertiaryphosphine, most preferably H, CO; n is 2 to 6, preferably 2; s is 1 to3. Preferably all the organic radicals are unsubstituted. However, ifsaid Ar, R and Q moieties are substituted, the substituents mustgenerally be unreactive with the products of, and during, carbonylationreaction and particularly during hydroformylation reaction.Representative non-limiting examples are described below.

Representative examples of the aromatic Ar groups include phenyl,fluorophenyl, difluorophenyl, tolyl, xylyl, benzoyloxyphenyl,carboethoxyphenyl, acetylphenyl, ethoxyphenyl, phenoxyphenyl, biphenyl,naphthyl, hydroxyphenyl, carboxyphenyl, trifluoromethylphenyl,tetrahydronaphthyl, furyl, pyrryl, methoxyethylphenyl, acetamidophenyl,dimethylcarbamylphenyl, and the like. If substituted, mono- anddisubstituted phenyl groups are preferred.

Preferred substituents of the Ar aromatic groups include C₁ to C₃₀,preferably C₁ to C₁₂ alkyl, alkoxy, acyl, acyloxy, acrylamido,carbamido, carbohydrocarbyloxy, halogen, phenoxy, hydroxy, carboxy andthe like.

Representative R organic groups include C₁ to C₁₀ hydrocarbyl,preferably C₁ to C₆ unsubstituted alkyl, and particularly preferred,phenyl, and C₁ to C₃ alkyl. Specific examples include methyl, propyl,hexyl, cyclohexyl, methylcyclopentyl, i-propyl, decyl, fluoropropylbenzyl, phenyl, naphthyl, fluorophenyl, tolyl, and the like.Particularly preferred R groups are methyl and phenyl.

The Q moiety in the composition include substituted and unsubstituteddivalent alkylene radicals bridging the P and Si atoms. Whenunsubstituted, the polymethylene radical is the formula (CH₂)_(m)wherein m is 2 to 14, preferably 2 to 3, and particularly preferredbeing 2, ethylene. The first segment of the Q alkylene group bound tothe phosphorous is preferably a--CH₂ CH₂ --group. Such a group isdesired to avoid undue steric hindrance of the phosphine ligand. Whenthe Q radical is substituted, the alkylene chain can also be interruptedwith a heteroatom such as ether oxygen, sulfide, and the like, and alsoby the phenylene group.

Representative examples of Q radicals include ethylene, trimethylene,tetradecamethylene, xylylene, oxy-bis ethyl, sulfone-bis ethyl,trimethylsilylethyl substituted trimethylene, and the like.

Representative examples of anions and organic ligands, represented bythe symbol X, are the following: H-, alkyl⁻, aryl⁻, substituted aryl⁻,CF₃ ⁻, C₂ F₅ ⁻, CN⁻, N₃ ⁻, COR⁻, where R is alkyl or aryl, acetate,acetylacetonate, SO₄ ²⁻, PF₄ ⁻, NO₂ ⁻, NO₃, O₂ ⁻, CH₃ O⁻, CH₂ ═CHCH₂ ⁻CO, C₆ H₅ CN, CH₃ CN, NO, NH₃, pyridine C₄ H₉)₃ P, (C₂ H₅)₃ N, chelatingolefins, diolefins and triolefins, tetrahydrofuran, CH₃ CN, triphenylphosphine. Preferred organic ligands are H, CO and tertiary phosphineand most preferably H and CO. Halogens may not be directly bonded to thetransition metal.

Representative examples of groups represented by the symbol (MX_(n))_(s)are Rh(CO)H, Ir(CO)H, Co (CO)₃ H Ru(CO)₂ H, and particularly preferredis Rh(CO)H.

The values of the integers represented by the symbols y, n, s, g in theabove-defined formula depend on the number of monoversus divalentorganic radical substituents (R vs. Q) on the silicon, and thecoordination number of the metal. Accordingly, these values, as definedabove, are interrelated to satisfy the valence requirements of thesilicon and the transition metal.

Although the complex catalyst compositions of the present invention arepreferably non-charged, they include compounds containing positivelycharged transition metal, particularly rhodium. These complexes arepreferably of the general formula:

    [Ar.sub.2 P(CH.sub.2).sub.m SiR.sub.3 ].sub.2 Rh.sup.+ (CO).sub.3 X.sup.-

wherein the meaning of Ar, R and m is the same as before, and X⁻ is ananion, preferably a non-coordinating anion, preferably selected from thegroup consisting of borate, aluminate, perchlorate, sulfonate, nitrate,fluorophosphate, and fluorosilicate. Representative examples of formulasinclude PH₄ B⁻, F₄ B⁻, ClO₄ ⁻, Ph₃ SO₃ ⁻, CF₃ SO₃ ⁻, NO₃ ⁻, F₆ P⁻, andF₆ Si₂ ²⁻.

Dependent on the subclass of the silylalkyl phosphine component used asan intermediate different types of the present complexes are derived,wherein the value of g is 1 to 6 and the value of g times y is 1 to 6;i.e.,

    ______________________________________                                        [Ar.sub.2 PQSiR.sub.3 ].sub.g.(MX.sub.n).sub.s                                                      g = 1-6; y = 1                                          [(Ar.sub.2 PQ).sub.2 SiR.sub.2 ].sub.g.(MX.sub.n).sub.s                                            2g = 1-6; y = 2                                          [(Ar.sub.2 PQ).sub.3 SiR].sub.g.(MX.sub.n).sub.s                                                   3g = 1-6; y = 3                                          [(Ar.sub.2 PQ).sub.4 Si].sub.g.(MX.sub.n).sub.s                                                    4g = 1-6; y = 4                                          ______________________________________                                    

Preferred hydroformylation catalyst compositions of the presentinvention are non-chelated trisphosphine and bisphosphine rhodiumcarbonyl hydride compositions of the generic formulae:

    [(Ar.sub.2 PQ).sub.y SiR.sub.4 -y].sub.g.Rh(CO)H, and

    {[Ar.sub.2 P(CH.sub.2).sub.m ].sub.y SiR.sub.4-y }.sub.g Rh(CO)H

wherein the meaning of Ar and R is as previously defined; m is 2 to 14,preferably 2 to 3, most preferably 2; y is 1 to 4, preferably 1 to 3,most preferably 2; g is 2 to 3, preferably 3.

Among this class of trihydrocarbylsilyl alkyl phosphine rhodiumcomplexes, preferred subgeneric classes are the following:

    {[(Ar.sub.2 P(CH.sub.2).sub.m ]SiR.sub.3 }.sub.3 Rh(CO)H

    {[(Ar.sub.2 P(CH.sub.2).sub.m ]SiR.sub.2 }.sub.3 Rh(CO)H

    {[Ar.sub.2 P(CH.sub.2).sub.m ].sub.3 SiR}.sub.3 Rh(CO)H

    {[(Ar.sub.2 P(CH.sub.2).sub.m ].sub.4 Si}.sub.3 Rh(CO)H

Some specifically preferred silylalkyl phosphine rhodium complexespossess short straight chain alkylene bridges between Si and P, e.g.,

    [(φ.sub.2 P(CH.sub.2).sub.m ].sub.y SiR.sub.4-y ].sub.g [Rh(CO)H]

wherein m is 2 to 14, preferably 2 to 3, R being C₁ -C₆ alkyl, andwherein the complexes can be oligomeric whenever the silylalkylphosphine has more than one phosphine group.

Among the preferred subgeneric examples of such compositions are thefollowing:

    [φ.sub.2 P(CH.sub.2).sub.m Si(CH.sub.3).sub.3 ].sub.3 Rh(CO)H

    [φ.sub.2 P(CH.sub.2).sub.m Siφ.sub.3 ].sub.3 Rh(CO)H

    {[φ.sub.2 P(CH.sub.2).sub.m ].sub.2 Siφ.sub.2 }.sub.3 Rh(CO)H

    {[φ.sub.2 P(CH.sub.2).sub.m ].sub.2 Si(CH.sub.3).sub.2 }.sub.3 Rh(CO)H

    {[φ.sub.2 P(CH.sub.2).sub.m ].sub.3 SiCH.sub.3 }.sub.3 Rh(CO)H

    {[φ.sub.2 P(CH.sub.2).sub.m ].sub.4 Si}.sub.3 (Rh(CO)H).sub.s

Representative examples of specifically preferred rhodium complexeswhich are non-limiting include:

    [Ph.sub.2 PCH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3 ].sub.3 Rh(CO)H

    [Ph.sub.2 PCH.sub.2 CH.sub.2 Si(n-C.sub.3 H.sub.7).sub.3 ].sub.3 Rh(CO)H

    [Ph.sub.2 PCH.sub.2 CH.sub.2 SiPh.sub.3 ].sub.3 Rh(CO)H

    [(Ph.sub.2 PCH.sub.2 CH.sub.2).sub.2 Si(CH.sub.3).sub.2 ].sub.3 Rh(CO)H

    [PH.sub.2 PCH.sub.2 CH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3 ].sub.3 Rh(CO)H

    [Ph.sub.2 PCH.sub.2 Si(CH.sub.3).sub.3 ].sub.3 Rh(CO)H

    [(Ph.sub.2 PCH.sub.2 CH.sub.2 CH.sub.2).sub.2 Si(CH.sub.3).sub.2 ].sub.3 Rh(CO)H

    [(Ph.sub.2 PCH.sub.2 CH.sub.2).sub.2 SiPh.sub.2 ].sub.3 Rh(CO)H

    [(Ph.sub.2 PCH.sub.2 CH.sub.2).sub.3 Si(CH.sub.3)].sub.3 Rh(CO)H

    [(Ph.sub.2 PCH.sub.2 CH.sub.2).sub.4 Si].sub.3 (Rh(CO)H).sub.s

Examples of preferred types of subgeneric complexes of other transitionmetals are:

    (φ.sub.2 PQSiR.sub.3).sub.3 Ir(CO)H

    (φ.sub.2 PQSiR.sub.3).sub.2 Ru(CO).sub.2 H.sub.2

    (φ.sub.2 PQSiR.sub.3)Co(CO).sub.3 H

Specific non-limiting examples of the above are the following:

    {[φ.sub.2 PCH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3 ]Co(CO).sub.3 }.sub.2

    [φ.sub.2 PCH.sub.2 CH.sub.2 CH.sub.2 Siφ.sub.3 ].sub.3 Ir(CO)H

    [φ.sub.2 PCH.sub.2 CH.sub.2 Si(n-C.sub.3 H.sub.7).sub.3 ]Ru(CO).sub.2 H.sub.2

Preparation of Complexes and Silylalkyl Phosphine Intermediates Therefor

For the preparation of the present compositions, standard methods oforganometallic chemistry synthesis are discussed in a comprehensivetext, "Advanced Inorganic Chemistry" by F. A. Cotton and G. Wilkinson(Interscience Publishers, New York, 1972) and are exemplified in theseries on "Inorganic Syntheses" particularly volume XV, edited by G. W.Parshall and published by McGraw-Hill Book Co., New York, 1974, and inU.S. Pat. No. 4,052,461 by H. B. Tinker and D. E. Morris.

For the preparation of the rhodium complexes, one of the specificallypreferred direct method of synthesis starts with rhodium chloride. Thismethod can be employed, e.g., for the synthesis oftris-(trihydrocarbylsilylalkyl diaryl phosphine) rhodium carbonylhydride according to the following general scheme: ##STR2##

Other preferred direct methods of complex preparation include thereaction of transition metal carbonyls or oxides, such as those ofrhodium with the silylalkyl phosphine ligand and CO/H₂. Specificallypreferred is the use of dicarbonyl acetylacetonate rhodium to form thesubject process complex is in which excess silyl phosphine ligand isreacted with the carbonyl complex and the resulting complex reduced withhydrogen. Organic salts of transition metals such as acetates can alsobe reacted with the ligand.

The complexes can also be prepared via an indirect method by reaction ofthe corresponding complexes of a triaryl phosphine, preferably triphenylphosphine, with the desired silylalkyl phosphine ligand, as definedhereinabove, preferably in excess, e.g.,

    (φ.sub.3 P).sub.3 Rh(CO)H+3φ.sub.2 PQSiR.sub.3 →(φ.sub.2 PQSiR.sub.3).sub.3 Rh(CO)H+3φ.sub.3 P.

This ligand exchange method is one of the preferred embodiment in theprocess. The above ligand exchange methods involving dicarbonylacetylacetonate rhodium and (PH₃ P)₃ Rh(CO)H can be preferably used toform the active catalyst in situ during the process, especially duringhydroformylation. The silyl ligand used is [(Ar₂ PQ)_(y) Si_(4-y]), asdefined herein.

In the case of rhodium catalysts, it is essential that the final complexformation be conducted in the absence of reactive halogen, i.e., metalbound halogen. Presence of halide in rhodium hydroformylation has beenfound to lead to severely reduced catalytic activity. Preferably lessthan 1 ppm by weight of halide ion, e.g., chloride ion, is present pergram of phosphine ligand in the reaction medium.

The above methods are also applicable to forming useful complexes in thesubject process where the metal is Fe, Co, Ru, Os and Ir.

In general, the silylalkyl diaryl phosphine ligands are more basic thanthe corresponding triaryl phosphines. This basicity difference is apositive factor in the above ligand substitutions providing the novel,completely or partially exchanged complexes, e.g., ##STR3##

The intermediate silylalkyl phosphine ligands employed in the presentinvention are prepared by any number of standard techniques. U.S. Pat.No. 3,907,852 and 4,083,803 to Oswald and Murrell and G.B. 925,721 toNiebergall are representative of techniques which may be successfullyemployed to prepare the intermediates.

One preferred synthesis technique involves the addition of diarylphosphines to unsaturated silanes:

    yAr.sub.2 PH+}[CH.sub.2 =CH(CH.sub.2).sub.k ].sub.g }.sub.y SiR.sub.4-y→{[Ar.sub.2 PCH.sub.2 CH.sub.2 (CH.sub.2).sub.k ].sub.g }.sub.y SiR.sub.4-y

wherein k ranges from 0 to 28 and y ranges from 1 to 4. Such additionsare preferably carried out via a radical mechanism in a free radicalmanner employing either a chemical initiator such asazobisisobutyronitrile, or radiation initiator. It is preferred thatsuch reactions be conducted in the presence of from a 5 to 100% excessover the stoichiometric amount required of the phosphine. Use of thisexcess has been found to improve the selectivity of the process.

It has also been observed that additions of phosphines to vinylicsilanes (k=0) occur with ease in the presence of radiation particularlyultraviolet light. The reactivity of the vinyl silanes is in markedcontrast to the rather sluggish behavior of the olefins having analogousstructures. In addition to the vinyl silanes, allyl silanes (k=1) areanother preferred class of reactant.

Another technique which may be employed in the preparation of the silylhydrocarbyl phosphine intermediate involved in the present invention isthe addition of silanes to unsaturated phosphines:

    yAr.sub.2 P(CH.sub.2).sub.k CH=CH.sub.2 +H.sub.y SiR.sub.4-y →[Ar.sub.2 P(CH.sub.2).sub.k CH.sub.2 CH.sub.2 ].sub.y SiR.sub.4-y

wherein k ranges from 0 to 28 and y ranges from 1 to 4.

These additions occur in an anti-Markovnikov manner via the mechanismdiscussed by C. Eaborn in the monograph "Organosilicon Compounds,"Academic Press, Inc., Publishers, New York, 1960, and in the patentreferences previously identified. Again, the preferred reactants are thevinylic and allylic materials, this time the phosphines.

Other methods for silylalkyl phosphine preparation employ displacementreactions. One type of reaction starts with phosphides, particularlyalkali metal phosphides, and chloro-, bromo-, or iodo-alkyl silanes:

    yAr.sub.2 PMe+[Z(CH.sub.2).sub.m ].sub.y SiR.sub.4-y →[Ar.sub.2 P(CH.sub.2).sub.m ].sub.y SiR.sub.4-y +MeZ

wherein Me is Na, K, Li; m is 1 to 30; Z is Cl, Br, I. It is importantthat monophenylalkylphosphine be absent to insure high reactivity andpurity of the final product. Another technique starts with diaryl chloroor bromo phosphines and the corresponding Grignard derivatives of thesilicon compounds:

    Ar.sub.2 PZ+[ZMg(CH.sub.2).sub.m ].sub.y SiR.sub.4-y →[Ar.sub.2 P(CH.sub.2).sub.m ].sub.y SiR.sub.4-y +yMgZ.sub.2

wherein Z is chlorine, bromine. Particular care is to be taken to removeall impurities containing reactive halogen, e.g. by the extraction ofthe product by aqueous caustic

CARBONYLATION PROCESSES EMPLOYING HOMOGENEOUS SILYLALKYLPHOSPHINE-TRANSITION METAL COMPLEX CATALYSTS

It has been discovered that carbonylation reactions, particularlyhydroformylation reactions, which involve the reaction of unsaturatedorganic compounds with CO, or CO and hydrogen mixtures can besuccessfully practiced in the presence of catalytically effectiveamounts of silylalkyl diaryl phosphine-Group VIII Transition metalcomplexes, described hereinabove. Carbonylation reactions are describedin detail in the earlier referred to Falbe monograph. Main types ofcarbonylation reactions catalyzed by the present complexes are theRoelen reaction (hydroformylation) of olefins with CO and H andsubsequent aldolization reactions; the Reppe reaction (metal carbonylcatalyzed carbonylation) mainly of olefins, acetylenes, alcohols andactivated chlorides with CO alone or with CO plus either alcohol oramine or water; and ring closure reactions of functional unsaturatedcompounds such as unsaturated amides with CO. The organic reactants arepreferably olefinically unsaturated compounds, more preferably olefinichydrocarbons.

The most preferred type of carbonylation reaction, encompassed withinthe scope of the subject invention process, is a selectivehydroformylation comprising reacting a C_(n) olefinically unsaturatedcompound with a mixture of carbon monoxide and hydrogen in the presenceof a hydrocarbyl silylalkyl diaryl phosphine halogen free rhodiumcomplex as a catalyst, as described hereinabove, to produce mainly aC_(a+1) aldehyde, preferably via hydroformylation at the lesssubstituted vinylic carbon. By the term "C_(n) ", as used herein, ismeant an olefinically unsaturated compound containing "n" carbon atoms.By the process of hydroformylation, through which the elements offormaldehyde, i.e., H and CHO, are added to a double bond linkage, aC_(n) olefinically unsaturated organic compound will be converted to aC_(n+1) aldehyde, assuming hydroformylation of one double bond. Wheresaid C_(n) compound contains more than one double bond, the carbonnumber will be increased by one for each double bond undergoinghydroformylation. Thus, multiple hydroformylation of a diolefin andhigher is also encompassed within the intent of this subject process.Where said C_(n+1) aldehyde further undergoes aldolization, theresulting compound is termed herein, a C_(2n+2) aldol aldehyde. Inaddition to the aldol aldehyde, higher aldehydes are also formed, suchas trimers, tetramers and the like.

Preferred catalysts for use in the subject hydroformylation process areof the formula:

    {[(C.sub.6 H.sub.5).sub.2 P(CH.sub.2).sub.m ].sub.y SiR.sub.4-y }.sub.g [Rh(CO)H]

wherein m ranges from 1 to 30, preferably 2 to 14, most preferably 2 to3; y ranges from 1 to 4, preferably 1 or 2, most preferably 1; g is 2 to3, most preferably 3; R is C₁ to C₆ alkyl or phenyl, preferably methyl,ethyl, n- or i- propyl or phenyl.

Specific preferred catalysts are:

    {[(C.sub.6 H.sub.5).sub.2 P(CH.sub.2).sub.2 ].sub.2 Si(CH.sub.3).sub.2 }.sub.3 [Rh(CO)H];

    {[(C.sub.6 H.sub.5).sub.2 P(CH.sub.2).sub.2 ]Si(CH.sub.3).sub.3 }.sub.3 Rh(CO)H;

    {[(C.sub.6 H.sub.5).sub.2 PCH.sub.2 CH.sub.2 ].sub.3 SiCH.sub.3 }.sub.3 Rh(CO)H; and

    {[(C.sub.6 H.sub.5).sub.2 PCH.sub.2 CH.sub.2 ].sub.4 Si}.sub.3 Rh(CO)H;

and particularly the first two species.

Particularly in the case of the rhodium complex hydroformylationcatalysts, organic solvents, other than simple hydrocarbons can be usedwhich are preferably of weak, nonsubstituting ligand character.Representative solvents include triaryl phosphines, such as triphenylphosphine; triaryl stibines; triaryl arsines. Other representativeorganic solvents are ketones such as acetophenone, diphenyl ketone;hydrocarbyloxyethyl alcohols, including phenoxyethanol, andmethoxytriglycol; polyethylene glycol, 2-ethylhexylacetate, dipropyladipate, ethylene glycol diacetate, 1,4-butanediol, dimethyl formamide,n-methylpyrrolidine, 4-hydroxybutyl-2-ethylhexanoate, organic siliconecompounds such as diphenyl dipropyl silane, and the like. More preferredligand solvents are triaryl phosphines, or an excess of the samesilylalkyl phosphine ligand [(Ar₂ PQ)_(y) Si_(4-y) ], as describedhereinabove, which is complexed with the (MX_(n))s group. In general,the preferred solvents, particularly the ligands, stabilize the catalystsystem and increase its selectivity, particularly the ratio of linearversus branched products.

In case of continuous hydroformylations of olefins, particularly higherolefins, ethylene wherein the volatile primary aldehyde reactionproducts are continuously removed, the nonvolatile secondarycondensation products tend to become the main solvents. Such inert,nonvolatile oxygenated organic solvents, preferably of carboxylic esterand alcohol character, are advantageously used.

The hydroformylation of olefins can be advantageously run in the presentprocess in a manner coupling it with aldol condensation. The catalystuseful in combined hydroformylation-aldolization is the rhodium catalystcomplex of the above-described general subject formula. For example, inthe case of butene-1, the following conversions can be carried out in acombined process: ##STR4## To realize such a conversion of a C_(n)olefin to an unsaturated or saturated C_(2n+2) aldol aldehyde, thepresent catalyst systems preferably contain a base aldol condensationcatalyst such as KOH. A preferred concentration of the base, i.e.,alkali hydroxide, is between about 0.01 and 1%, and preferably between0.05 and 0.5 wt% of the total reaction mixture.

To insure high n.i. ratios in the process, preferably ether alcohols areutilized as solvents such as methoxytriglycol, phenoxy-ethanol and thelike to insure preferably a homogeneous reaction medium.

Further details of the process include the necessary use of anisolation/recovery step wherein at least a portion of liquid reactionmixture is removed from the reaction zone in the process and recoveringthe product C_(2n+2) aldehyde, thereby conventional methods.Hydrogenated products of the resulting aldol aldehydes are also formedin the reaction mixture, which can be insolated. A preferred catalystfor use in the process is tris(2-trimethylsilylethyl diphenyl phosphine)rhodium carbonyl hydride. Preferably the H₂ /CO molar ratio is greaterthan three, the ligand/Rh metal molar ratio is greater than 140, and thetemperature is between 120°-175° C. Further description of the detailsof the general process using similar Rh-type catalysts can be found inSer. No. 120,971 and PCT US80/00213, published Aug. 21, 1980, bothhereby incorporated by reference.

Hydroformylation Process Conditions

The carbonylation processes catalyzed by the present silylalkylphosphine catalysts described herein can be carried out advantageouslyunder the usual reaction conditions such as those described in theearlier referenced Falbe monograph.

The reaction and particularly the rhodium complex catalyzedhydroformylation of olefinic compounds, preferably olefins in the 2 to40 carbon range, especially olefinic hydrocarbons such as mono-, di- andtriolefins can be advantageously carried out, however, over a broadrange of process conditions. This above-stated carbon range is notlimiting, however, since uncross-linked polybutadiene of MW up to15,000, and the like, is also operable.

The olefinic reactants in the present hydroformylation process can beterminally or internally unsaturated and be linear or branched openchain or of cyclic structure. The internal olefins must contain at leastone, preferably two, hydrogens on the vinylic carbons. Details of olefinreactivities are incorporated by reference to Ser. No. 120,971.Terminally olefinic reactants, particularly alpha-olefins are preferred.Among the most preferred olefin reactants are C₂ to C₁₂ olefins.Representative examples include 1-tricosene, cyclohexane, ethylene,propylene, butenes and pentenes, hexenes, octenes, decenes, dodecenes,and the like particularly propylene, 3-methylbutene-1, butene-1,butene-2, including cis and trans isomers, isobutylene, 2-ethylexene-1,octene-1, hexene-1, hexene-3, pentene-1, octene-1, ethylene, andmixtures thereof. Particularly preferred are propylene, butene-1 andmixtures thereof with butene-2.

Exemplary diolefin reactants are divinyl cyclohexane and 1,7-octadiene.Di-and polyolefin reactants are preferably non-conjugated in character.

Substituted olefinic reactants can be also advantageously used as longas the substituent does not interfere with the catalyst system and isstable under the reaction conditions. Exemplary substituted olefins areacrylonitrile, methyl acrylate, trivinyl cyclohexane acroleindimethylacetal, allylacetate, allyl t-butyl ether allyl alcohol, methyl oleate,3-butenyl acetate, diallyl ether, allyl chlorobenzene,dicyclopentadiene, 6-hydroxyhexene.

It is to be noted that refinery streams of olefins, containing paraffinby-products such as C₁ -C₁₀ paraffins, inert gases, or entrained inertaromatics, are also applicable within the scope of this inventionprocess.

The hydroformylation of a C_(n) olefin, with the exception of ethylene,leads to a mixture of terminally and internally substituted C_(n+1)aldehydes. For example, the hydroformylation of propylene leads to amixture of iso- and n-butyraldehydes and hydroformylation of butene-1leads to a mixture of C₅ aldehydes, n-valeraldehyde andisovaleraldehyde, said mixtures having an "n/i" ratio of products. Thesubject process, in general, can yield high n/i ratios during hydroformylation of about 4:1 and higher.

Concentrations of the transition metal complex catalysts andparticularly the preferred rhodium complex catalysts can be employed inthe range of about 1×10⁻⁶ to 1×10⁻¹ mole metal complex per liter ofreaction mixture. Preferred concentrations are in the range of 1×10⁻⁵ to1×10⁻¹ molar and more preferably, 1×10⁻⁴ to 1×10⁻² molar. The catalystconcentrations used are directly affected by the concentration of freeligand present, especially the excess silylalkyl phosphine ligand. Ingeneral, the higher the ligand concentration, the higher the metal levelrequired for a certain reaction rate. In addition to the above-statedranges, higher and lower levels of complex catalyst may be effectivelyemployed in the process.

The amount of tertiary organo phosphine ligand used in the process canbe from about 1 to 95 weight percent of the entire reaction mixture,which includes tertiary phosphine used in the silyl complex and anamount of excess phosphine. Preferably, the amount of excess ligand inthe reaction mixture is from about 10 wt. percent to about 65 weightpercent. Concentrations of the excess phosphine ligand can be from 0.2to 3, preferably 0.5 to 2.7, or most preferably 0.5 to 1.5 phosphineequivalent per liter. In the case of trimethylsilylethyl diphenylphosphine, the latter range means a weight concentration ranging fromabout 14 to about 47%. At an appropriate rhodium concentration, thereaction can be carried out using the excess phosphine as the solvent.However, in general, the phosphine concentration is limited to 75 weightpercent of the reaction mixture. Sufficient excess phosphineconcentration is used in the preferred process to carry out the reactionat the desired temperature under the desired conditions with the desiredselectivity and activity maintenance. The rhodium complex concentrationis then adjusted to achieve the desired reaction rate.

The mole ratio of total tertiary phosphine ligand to mole equivalentrhodium complex, L/Rh, is generally above 100, preferably being above120, more preferably above 240, most preferably above 400. In general,higher ratios are selected when the desired operation is a continuous,rather than a batchwise operation. However, there may be instances wherevery low L/Rh ratios below 100 are desired and these also areencompassed within the scope of this invention.

In general, ligands of high phosphorus content are desired to achievethe required phosphine equivalency by using the minimum weight. However,to reduce the volatility of the phosphine ligands, phosphines of highmolecular weight are desired. These two factors can be best compromised,for example, by using non-chelating bis-phosphine and polyphosphineligands such as (Ph₂ PCH₂ CH₂)₂ Si(CH₃)₂ and (Ph₂ PCH₂ CH₂)₃ SiCH₃.

The selectivity of the present rhodium complex hydroformylationcatalysts generally also depends on the molar ratio of the gaseous H₂and CO reactants. To keep the partial pressure of CO desirably low, thisH₂ /CO ratio is generally above about 1 and preferably between 2 to 100,and preferably between 2 and 20.

The present process can be suitably operated at low total processpressures. Generally desired pressures are between about 15 and 1000psia, and and more preferably between about 55 and 500 psia.

The above pressure limitations reflect a moderate sensitivity of therhodium complex catalyst employed to the partial pressure of CO used.Although higher values can be effectively used, the total partialpressure of CO in the feedstream is preferably less than about 400 psiamore preferably less than 100 psia, and most preferably in the range of50-1 psia. In general, when the CO partial pressure is too high and thephosphine concentration is too low, the catalyst complex can becomedeactivated due to the formation of carbonyl derivatives.

The partial pressure of hydrogen in general has no critical upper limitby itself from the viewpoint of hydroformylation. Preferred partialpressure of hydrogen are between about 50 and 300 psia, although higherand lower partial pressures are also operable. When the H₂ /CO ratio istoo high and/or the CO concentration is insufficient, however, therelative rates of competing hydrogenation and isomerization reactionstend to increase.

In the upper temperature range of the present process, i.e., 130°-200°C. a significant part of the total pressure can be maintained by theaddition to the olefin feedstock of either a volatile, reactive orunreactive olefin, such as butene-2, or a saturated, aliphatichydrocarbon, such as C₁ to C₄₀ paraffinic hydrocarbon, or aromatichydrocarbon, or by an inert gas. A preferred mode of operationincorporates a paraffinic hydrocarbon in the olefin feed and allows afacile continuous product flashoff while assuring a higher solubility ofthe gaseous reactants in the liquid reaction mixture. A C₁ -C₁₂ andpreferably, C₁ -C₅, paraffin possesses higher volatility and thus isespecially preferred for the hydroformylation of C₂ to C₅ olefins.

The operation of the present process can be optimized in a surprisinglybroad temperature range. The range of temperature is preferably between50° and 200° C., and preferably between 120° and 175° C. In addition,our novel catalysts are operable above 145° C. to 170° C. for thehydroformylation of C₄ and higher olefin. Compared to the TPP catalystsystem, the maintenance of the catalyst activity and selectivity at thehighest temperatures is particularly unique. High rates of selectivehydroformylation of 1-n-olefins can be realized and maintained to highconversion at 145° C. when using the present catalyst.

The present hydroformylation process can be carried out either in theliquid, vapor or in the gaseous state. A preferred process employs aliquid, more preferably homogeneous liquid, reaction phase with thepresent catalyst system dissolved, i.e., homogeneous catalyst.

Catalytic Intermediates in Rhodium Hydroformylation

The silyl alkyl diaryl phosphine rhodium complex catalyst compositionsof the present process were previously disclosed and exemplified. Fromthe view-point of selective hydroformylation, it is emphasized that insolution, and particularly under reaction conditions, the tris- andbis-phosphine rhodium complexes are present.

While we do not wish to be bound by the following theory, it is believedthat the equilibration of tris- and bis-phosphine rhodium carbonylhydride complexes as established via 31 P nmr studies: ##STR5## isrelated to the activity and selectivity of the present catalystaccording to the mechanism shown by FIG. 1.

Equilibration of the stable tris-phosphine complex to provide some ofthe highly reactive, coordinatively unsaturated trans-bis-phosphine isto occur in an active catalytic system. However, it is believed that inthe case of stable selective catalysts, most of the rhodium is presentin the stable tris-phosphine complex form.

The equilibration involves the reversible elimination and addition of aphosphine ligand. Its rate was found to depend on the temperature. Assuch, it was determined by 31 P nmr. It was also found that themaintenance of the equilibrium on the tris-phosphine side and thestabilization of the system, require an excess concentration of thephosphine ligand. The maintenance of the yellow color of catalystsolutions and the high selectivity of hydroformylation indicated thestability of the complex catalyst.

Comparative 31 P nmr studies of the known TPP catalyst plus TPP systemshowed that its mechanism is similar. However, the thermal activationand catalyst destabilization of this system occurs at lower temperatures(FIG. 3). On other words, the present tris(silyl diaryl phosphine)rhodium carbonyl hydride plus excess phosphine based systems aresurprisingly improved high temperature catalysts.

The stronger complexation of the trihydrocarbyl silyl alkyl diarylphosphine ligands to form the corresponding tris-phosphine rhodiumcarbonyl hydride complexes could also be established in competitivecomplexation with triaryl phosphines (FIG. 2). When equimolar amounts ofthe two different phosphines, such as SEP and TPP were used, mostly thetris-SEP rhodium carbonyl hydride was formed. However, there were sometris-phosphine complexes containing both types of ligands. When theratio of SEP to TPP was about 6, only the spectrum of the tris-SEPcomplex was observed. When the SEP to Rh ratio was 10 or higher, even alarge excess of TPP, e.g., a TPP/Rh ratio 100, would not lead to theformation of the tris-TPP complex.

The coordinatively unsaturated trans- bis-phosphine rhodium carbonylhydride can react with both olefins and carbon monoxide in a reversiblemanner. Complete reaction with CO leads to the formation of nonselectivecatalytic intermediates, i.e., mono-phosphine dicarbonyl hydrides##STR6## and/or irreversible catalyst deactivation (see FIG. 1).

It was found, via further 31 P nmr studies of catalyst solutions underpressure of synthesis gas of varying H₂ /CO ratio, that the ratio ofmonocarbonyl versus dicarbonyl complexes was increased by employing ahigh ratio of H₂ /CO and a high excess of the phosphine ligand.Comparative studies of the SEP versus TPP catalyst system have shownthat the TPP system had a higher tendency to form the undesireddicarbonyl complexes.

The results of 31 P nmr studies of the tris-phosphine rhodium complexformation were correlated with catalyst activity. Those silylalkyldiphenyl phosphines, which do not form tris-phosphines at roomtemperature, are not preferred ligands for the present selectivecatalysis. Substitution of the α-carbon and multiple substitution of theβ-carbon of the alkyl group Q in the generic branch ando-o'-substitutions of the aryl groups Ar, generally interfere withcomplete complexation because of steric hindrance, i.e., the desiredcatalyst formation.

Continuous Hydroformylation

Due to the improved thermal stability of the silyl alkyl diarylphosphine rhodium complex catalysts, a continuous mode of operation isparticularly preferred for olefin hydroformylation. When using ahomogeneous liquid catalyst system, such an operation can be of acontinuous plug flow type, including a step for catalyst recovery andthen recirculation. A quasi continuous use of the catalyst may consistof the cyclic operation of a unit for hydroformylation and then forproduct flashoff. Catalyst concentration by continuous product flashoffor other methods of catalyst recovery may invole complete or partialrecycle, such as "recycle flashoff process" and by this form is meantseparation/isolation of products out of the reactor by means of drawingoff liquid reaction mixture and conducting separation by conventionaltechniques, e.g., distillation under reduced pressure, generally underdifferent process conditions, than those which are present in thereactor. However, a preferred method of operation involves continuousproduct flashoff, wherein the mixture of product aldehydes iscontinuously removed from the vapor phase of the reaction mixture.

In the present continuous product flashoff process, the aldehyde productof the hydroformylation is continuously removed as a component of avapor mixture while the CO, H₂ and olefin reactants are continuouslyintroduced. This process preferably includes the recirculation of mostof the unreacted reactants in the gaseous state and the condensation andthereby removal of most of the aldehyde and aldehyde derivativeproducts. Additional olefin, CO and H₂ are added as required to maintainaldehyde production and optimum process parameters. The space velocityof the gas stream is appropriately adjusted and additional gas purge isused as required to maintain production and catalyst activity. Since therhodium complex is not volatile, no catalyst losses occur. If thephosphine ligand is volatile, additional phosphine is added occasionallyto maintain its concentration in the reaction mixture.

Also, an embodiment of this invention is a process for continuoushydroformylation which comprises reacting a C₂ to C₆ olefin, preferablya 1-n-olefin and particularly preferred olefins being propylene andbutene-1, with CO and H₂ in the presence of a tris- and bis-(silyl alkyldiaryl phosphine) rhodium carbonyl hydride catalyst as described aboveand in the presence of excess phosphine ligand. According to thismethod, reactants, preferably all the reactants, are continuouslyintroduced into a reactor comprising dissolved catalyst and ligand in aliquid reaction mixture having preferably no added solvent and whereinat least some, preferably most, of the aldehyde products being a mixtureof C₅ aldehydes where butene-1 is the reactant, are continuously removedin the vapor phase. It is preferred in this process to have at leastsome of the reagents and products recirculated. The process is carriedout by having an appropriately limited partial pressure of carbonmonoxide, preferably below 200 psi and appropriately high concentrationof excess phosphine ligand relative to the catalyst complex, preferablyabove 1 weight percent, more preferably above 5 weight percent. Theseimprovements produce and maintain an effective catalyst system of highselectivity to aldehyde products.

Specifically preferred embodiments included in the above description iswherein the process is a continuous hydroformylation process forconverting butene-1 to a mixture of C₅ aldehyde, or converting propyleneto a mixture of butyraldehydes preferably having an n/i ratio of aboveabout 4:1, wherein said catalyst is [(Ph₂ PCH₂ CH₂)₂ Si(CH₃)₂ ]₃Rh(CO)H, and said product aldehydes can be continuously removed from thevapor phase of said reaction mixture or recovered by recycle flashoff asdescribed herein.

During the continuous product flashoff operation, relativelynon-volatile aldehyde oligomers are formed and concentrated in theliquid reaction mixture. The oligomeric hydroxy substituted carboxylicester condensation and redox disproportionation products formed duringpropylene hydroformylation were disclosed in U.S. Pat. No. 4,148,830 byPruett and Smith. This recent patent of Pruett and Smith claims the useof aldehyde condensation products as solvents in triphenyl phosphine(TPP) rhodium complex catalyzed alpha-olefin hydroformylation. Anotherrecent patent by Brewester and Pruett, i.e., U.S. Pat. No. 4,247,486,claims a TPP-Rh complex catalyzed continuous product flashoff process insuch solvents.

In the present work, it was found that derivatives, mainly trimers,analogous to the butyraldehyde trimers, are formed during 1-butenehydroformylation from valeraldehydes. The general structure of theisomeric trimers formed during the hydroformylation of C₃ to C₆ is thefollowing: ##STR7## wherein R is C₂ to C₅, preferably C₃ alkyl.

The above aldehyde trimer is generally the main derivative and at theequilibrium conditions of the preferred continuous flashoff process, itcan automatically become the main solvent component. When this occurredduring 1-butene hydroformylation with the present catalysts, selectivityand production rate could be maintained and the concentration of thetrimer could be limited to an equilibrium value.

In the continuous product flashoff operation, carbonylations, especiallythe hydroformylation of olefins is advantageously carried out at a lowolefin conversion, preferably at a 20 to 80% olefin conversion. Aldehydeproduction rates are preferably between 0.1 to 5 g mole/liter/hour, morepreferably between 0.5 and 2 g mole/liter/hour. The loss of catalystactivity is preferably less than 0.3% per day.

Operating in this manner, with optimized reactant ratios, particularlyhigh linear to branched aldehyde product ratios are obtained from1-n-olefins.

The continuous process can be also employed for the selective orcomplete conversion of different types of olefins. For example, amixture of 1- and 2-butenes can be hydroformylated to produce mainlyn-valeraldehyde and 2-butene. Similarly, a mixture of 1-butene, 2-buteneand i-butene can be converted selectively to varying degrees. The olefinfeedstream can also contain C₁ -C₄₀ paraffinic hydrocarbons, preferablyC₁ -C₁₂ and more preferably C₁ -C-₅ paraffinic hydrocarbons.

Using the present catalyst of improved thermal stability, theapplication of continuous or batch flashoff processes can be extended tohigher olefins lieading to non-volatile products. The preferred olefinsfor continuous product flashoff are of the C₂ to C₆ range and n-1-olefintype. 1-Butene is a particularly preferred reactant.

A further embodiment of the subject process is a combinedisomerization-hydroformylation process wherein an internal olefin, suchas butene-2, is catalytically isomerized to provide an equilibriummixture containing a terminal olefin, i.e., butene-1, which is thenpreferentially hydroformylated.

Catalysts capable of performing both functions are preferably cobaltcatalysts of the formula:

    [(Ar.sub.2 PQ).sub.y SiR.sub.4-y ].sub.g.(CoX.sub.n).sub.s

wherein Ar, Q, y, r, G, X, n, s are as defined hereinabove.

The process can be conducted under generally the same process conditionsas described in the previously referred Falbe monograph, forhydroformylation with respect to temperature, pressure, H₂ and COpartial pressures, catalyst and excess ligand concentrations, batch andcontinuous mode operations, and the like. It is particularly preferredto have temperatures between 150° and 200° C. and pressures between 500to 2000 psia.

A preferred catalyst for use in this embodiment is [Ph₂ PCH₂ CH₂Si(CH₃)₃ ]Co(CO)₃ H, and a preferred internal olefin reactant beingbutene-2, being converted to butene-1.

The following examples are illustrative of the best mode of carrying outthe invention process, as contemplated by us, and should not beconstrued to be limitations on the scope or spirit of the instantinvention.

EXAMPLE I. Preparation of Silylalkyl Diaryl Phosphine Ligands EXAMPLES1-8

The silylalkyl diaryl phosphine ligand components of the present rhodiumcomplexes were prepared during the present work.

The generally employed method for ligand preparation was the freeradical chain addition of diphenyl phosphine to a vinylic compound in ananti-Markovnikov manner.

    Ph.sub.2 PH+CH.sub.2 +CHR→Ph.sub.2 PCH.sub.2 CH.sub.2 R

As a rule, such additions were initiated in a homogeneous liquid phaseby broad spectrum ultraviolet light at 15° C. The rate of additiondepended strongly on the type of the olefinic compound employed. Ingeneral, compounds of vinylic substitution were highly reactive whileallylic derivatives were sluggish to react. The reaction times wereaccordingly varied. The selectivity of the additions could be improvedby using more than the equivalent amount, generally 10% excess, of thephosphine adding agent. In the case of vinylic derivatives, this reducedthe oligomerization of the unsaturated component. In general, no addedsolvents were used. During the reaction, the conversion of reactants toproducts (and by-products) was followed by gas liquid chromatography(glc) and/or proton magnetic resonance spectroscopy (pmr). Usually theglc peak intensities were used to make quantitative estimates of thecompositions. For identification of the product structures mainly nmrwas used.

When the desired conversion was reached, the reaction mixture wasusually fractionally distilled in high vacuo to obtain the pure adductproduct. Most of the pure adducts were clear, colorless, liquids at roomtemperature. The monophosphines were mobile, the bisphosphines wereviscous.

The expected structures of the isolated products were confirmed by prm.Elemental analyses were also performed to check the productcompositions.

The pure phosphines were studied to determine their basicity, bypotentiometric titration and indirectly by ³¹ P nmr. The results ofdirect basicity determination will be given in the overview tables,together with the other analytical characteristics of the free phosphineligands. The ³¹ P nmr chemical shift values for the free ligands will belisted as comparative values when discussing the ³¹ P nmr of theirrhodium complexes.

The phosphine basicity determinations via potentiometric titrations wereperformed according to the method of C. A. Streuli. For reference seeAnalytical Chemistry, Vol. 31, pages 1652 to 1654 in 1959 and Vol. 32,pages 985 to 987 in 1960. Half neutralization potentials (HNP's) of thephosphines were determined using perchloric acid as a titrant and purenitromethane, free from weakly basic impurities, as a solvent. Thevalues obtained were subtracted from the HNP of a stronger organic base,diphenyl-guanidine, which served as a daily standard reference. Theresulting ΔHNP values of the phosphines are indirectly related to theirbasicity. In case of phosphines, which were also studied by Streuli,somewhat different ΔHNP values were obtained in the present work. Sinceion exchange resin purified nitromethane was used in the present work,the reported values should be more correct.

A number of trihydrocarbylsilylethyl and -propyl diphenyl silanes wereprepared by adding dipenyl phosphine to the corresponding vinylic orallylic silane. The preparation, physical properties and analyticalcomposition of seven compounds are summarized in Table I. The table alsoshows the basicity characteristics of the products as characterized bytheir ΔHNP values. It is noted that all the trihydrocarbylsilylalkyldiphenyl phosphines are much stronger bases than triphenyl phosphine(Ph₃ P: ΔHNP=510).

                                      TABLE I                                     __________________________________________________________________________    Preparation, Physical Properties and Composition of Silyl Substituted         Alkyl Diphenyl Phosphine Ligands                                                                             Ligand                                         Ex-                            Bp, °C.,/                               am-                            mm   Distd.                                                                            Elemental Composition,                                                                          Inverse             ple               Unsaturated  (Mp.,                                                                              Yield                                                                             Calcd.   Found    Basicity,           No.                                                                              Structure of Ligand                                                                          Reactant Used                                                                              °C.)                                                                        ˜%                                                                          C  H  P  C  H  P  Δ             __________________________________________________________________________                                                              HNP                 1  Ph.sub.2 PCH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3                                               CH.sub.2 ═CHSi(CH.sub.3).sub.3.sup.a                                                   115-118/                                                                           81  71.29                                                                            8.09                                                                             10.81                                                                            71.98                                                                            8.12                                                                             10.59                                                                            385                                                0.075                                          2  Ph.sub.2 PCH.sub.2 CH.sub.2 Si(C.sub.3 H.sub.7).sub.3                                        CH.sub.2 ═CHSi(C.sub.3 H.sub.7).sub.3.sup.b                                            155-156/                                                                           63  74.54                                                                            9.52                                                                             8.36                                                                             74.35                                                                            9.23                                                                             8.37                                                                             385                                                0.10                                           3  Ph.sub.2 PCH.sub.2 CH.sub.2 SiPh.sub.3                                                       CH.sub.2 ═CHSiPh.sub.3.sup.c                                                           (128-                                                                              --  81.32                                                                            6.19                                                                             6.55                                                                             80.97                                                                            6.18                                                                             6.71                                                                             413                                                131.sup.d)                                     4  (Ph.sub.2 PCH.sub.2 CH.sub.2).sub.2 Si(CH.sub.3).sub.2                                       (CH.sub.2 ═CH).sub.2 Si(CH.sub.3).sub.2.sup.a                                          238-239/                                                                           84  74.35                                                                            7.07                                                                             12.78                                                                            73.65                                                                            6.90                                                                             12.59                                                                            434                                                0.20                                           5  Ph.sub.2 PCH.sub.2 CH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3                                      CH.sub.2 ═CHCH.sub.2 Si(CH.sub.3).sub.3.sup.a                                          150/0.10                                                                           50  71.96                                                                            8.38                                                                             10.31                                                                            72.27                                                                            8.29                                                                             10.25                                                                            408                 6  Ph.sub.2 PCH.sub.2 Si(CH.sub.3).sub.3                                                        [ClCH.sub.2 Si(CH.sub.3).sub.3 ].sup.e                                                     129-130/                                                                           86  70.55                                                                            7.77                                                                             11.37                                                                            70.01                                                                            7.64                                                                             11.36                                                                            404                                                0.2                                            7  (Ph.sub.2 PCH.sub.2 CH.sub.2 CH.sub.2).sub.2 Si(CH.sub.3).sub.2                              (CH.sub.2 ═CHCH.sub.2).sub.2 Si(CH.sub.3.sup.a).sub.                      2            248-250/                                                                           48  74.97                                                                            7.45                                                                             12.08                                                                            74.96                                                                            7.45                                                                             12.00                                                                            420                                                0.1                                            __________________________________________________________________________     .sup.a The reactant was a purchased chemical reagent.                         .sup.b The reactant was prepared from tripropyl chloro silane by reacting     it with vinyl magnesium bromide.                                              .sup.c The reactant was prepared from vinyl trichloro silane by reacting      it with the appropriate Grignard reagent.                                     .sup. d The product was recrystallized from cyclohexanetoluene.               .sup.e The product was prepared from chloromethyl trimethyl silane by         reacting it with lithium diphenyl phosphide.                                  .sup.f Relative half neutralization potential compared to that of dipheny     guanidine.                                                               

Accounts of the individual experiments are given in the following.

EXAMPLE 1 Trimethylsilylethyl Diphenyl Phosphine

    Ph.sub.2 PH+CH.sub.2 =CHSi(CH.sub.3).sub.3 →Ph.sub.2 PCH.sub.2 CH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3

A magnetically stirred mixture of 46.5 g (0.25 mole) diphenyl phosphineand 25 g (0.25 mole) of vinyl trimethyl silane, in a closed cylindricalquartz tube, was irradiated from about 3 cm distance with two 75 WattHanau tube immersion lamps, with a wide spectrum of ultravioletirradiation, in a 15° C. water bath for 26 hours. A proton magneticresonance spectrum of a sample of the resulting mixture exhibited nosignificant peaks in the vinyl region indicating a substantiallycomplete addition.

The reaction mixture was distilled in vacuo to obtain 61 g (81%) of thedesired trimethylsilylethyl diphenyl phosphine adduct, as a clearcolorless liquid, having a boiling range of 109°-110° at 0.1 mm (TableI).

The selectivity to provide the desired adduct was increased when thediphenyl phosphine reactant was employed in a 10 mole % excess.

EXAMPLE 2 Tripropylsilylethyl Diphenyl Phosphine ##STR8##

To prepare the vinyl tripropyl silane reactant, chloro tri-n-propylsilane was reacted with vinyl magnesium bromide in refluxingtetrahydrofuran.

After removing the THF solvent by distillation, the residual product wastaken up in ether, then washed with ice water and then with 5% aqueoussodium hydrogen carbonate. The ether solution was then dried overanhydrous sodium sulfate and distilled to obtain vinyl tripropyl silane,bp. 75°-77° C. at 11 mm.

The vinyl tripropyl silane was then reacted with diphenyl phosphine withu.v. initiation for 86 hours in a manner described in the previousexample. The conversion was about 95%. The mixture was fractionallydistilled to yield the pure product as a clear, colorless, mobile liquid(see Table I.)

EXAMPLE 3 Triphenylsilylethyl Diphenyl Phosphine ##STR9##

To obtain the vinyl triphenyl silane intermediate, vinyl trichlorosilane was reacted with phenyl magnesium bromide in an ether-THF solventmixture. The resulting product was worked up in a manner described inthe previous example. The product was a low melting solid which could bedistilled in vacuo using a hot condenser. At room temperature, thedistillate solidified to yield a white crystalline compound, mp. 60°-65°C. Pmr confirmed the expected vinyl triphenyl silane structure.

Anal. Calcd. for C₂₀ H₁₈ Si: C, 83.86; H, 6.33. Found: C, 83.92; H,6.34.

The vinyl triphenyl silane was reacted with 10% excess of diphenylphosphine. To maintain a homogeneous reaction mixture, a temperature of80° C. and cyclohexane solvent were employed. After the usual u.v.initiated addition, the reaction mixture was allowed to cool to roomtemperature. This resulted in the crystallization of thetriphenylsilylethyl diphenyl phosphine adduct. To obtain it in a pureform, the adduct was filtered and recrystallized from a four to onemixture of cyclohexane and toluene. A white crystalline product havingthe properties shown in Table I was obtained.

EXAMPLE 4 Bis-(Diphenylphosphinoethyl) Dimethyl Silane ##STR10##

A mixture of 9.0 g (0.8 mole) dimethyl divinyl silane and 32.7 g (0.176)diphenyl phosphine (10% excess over equivalent amounts) was reacted for22 hours in the manner described in Example 1. The reaction mixture wasfractionated in vacuo to obtain minor amounts of a clear, colorless,slightly viscous liquid monoadduct, and major amounts of a clear,colorless, highly viscous liquid diadduct, i.e., the desiredbis-(diphenylphosphinoethyl) dimethyl silane (Table I). The lattersolidified to a crystalline solid on standing and was readilyrecrystallized from hexane.

EXAMPLE 5 Trimethylsilypropyl Diphenyl Phosphine

    Ph.sub.2 PH+CH.sub.2 =CHCH.sub.2 SiCH.sub.3).sub.3 →Ph.sub.2 PCH.sub.2 CH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3

A mixture of 22.8 g (0.2 mole) allyl trimethyl silane and 27.2 g (0.2mole) diphenyl phosphine was reacted for 158 hours in the mannerdescribed in Example 1. A subsequent fractional distillation, yieldedthe desired pure adduct as a clear, colorless liquid (Table 1).

EXAMPLE 6 Trimethylsilylmethyl Diphenyl Phosphine

    Ph.sub.2 PLi+ClCH.sub.2 Si(CH.sub.3).sub.3 →Ph.sub.2 PCH.sub.2 Si(CH.sub.3).sub.3

The known but unavailable trimethylsilylmethyl diphenyl phosphine wasderived via reacting chloromethyl trimethyl silane with lithium diphenylphosphide in an ether-hexane mixture. After removing the lithiumchloride by-product by filtration, the product was isolated as a clear,colorless liquid by fractional distillation in vacuo (Table 1).

EXAMPLE 7 Bis-(Diphenylphosphinopropyl) Dimethyl Silane ##STR11##

A mixture of 70 g (0.5 mole) dimethyl diallyl silane and 204.6 g (1.1 mmole, 10% excess over equivalent amounts) of diphenyl phosphine wasreacted in the manner described in Example 1 at 40° C. The addition wasslow. After 24 hours, only about 10% of the diphenyl phosphine reacted.The irradiation of the reaction mixture was continued for a total of 160hours. A subsequent fractional distillation provided 46 g of monoadduct,as a clear, slightly viscous liquid monoadduct of bp. 122°-134° C. at0.05 mm and 113 g of the desired diadduct (Table 1) as a clear, lightyellow, viscous liquid.

Anal. Monoadduct C₂₀ H₂₇ PSi. Calcd.: C, 73.57; H, 8.34, P, 9.59. Found:C, 73.79; H, 8.26; P, 9.66.

EXAMPLE 8 Bis-(Diphenylphosphinoethyl) Diphenyl silane ##STR12##

About 2 moles of diphenyl phosphine were added sequentially to one moleof divinyl diphenyl silane to yield mostly the desired diadduct whichcrystallized on standing; recrystallization from heptane provided thepure product.

EXAMPLE 9 Tris-(Diphenylphosphinoethyl) Methyl Silane ##STR13##

A mixture of 37.3 g (0.3 mole) trivinyl methyl silane and 175.8 g (0.945mole) diphenyl phosphine was reacted at 95° C. with u.v. lightinitiation in quartz pressure tube, in the manner described in Example1, until about 50% of the diphenyl phosphine was converted. A subsequentdistillation of the resulting reaction mixture in vacuo under nitrogenresulted in the isolation of the expected adducts.

The monoadduct (29 g) was obtained as a clear, colorless mobile liquidof about bp. 132° C. at 0.05 mm. The diadduct (51 g) was a slightlyhazy, colorless viscous liquid at room temperature. It distilled atabout 240° C. at 0.05 mm. The distillation residue (50 g, 24.5%) mostlyconsisted of the triadduct.

In another experiment, the reaction mixture was further irradiated untilmost of the diphenyl phosphine has reacted. The excess diphenylphosphine (14.5 g) was then recovered from the reaction mixture byvacuum stripping at 220° C. For recrystallization, the residual productwas dissolved in a 3 to 2 mixture of hot toluene and methanol to obtaina 28% solution. On cooling to -30° C., the desired triadductcrystallized and was isolated by filtration with suction and washed withmethanol. The dry product weighed 160 g (78%) and melted between 98° and101° C. A proton nmr spectrum of the product supported the assumedtris-(diphenylphosphinoethyl) methyl silane structure.

EXAMPLE 10 Tetrakis-Diphenylphosphinoethyl) Silane

    Si(CH=CH.sub.2).sub.4 +4Ph.sub.2 PH→Si(CH.sub.2 CH.sub.2 PPh.sub.2).sub.4

A mixture of 27.2 g (0.2 mole) of tetravinyl silane and 149.5 g (0.804mole) diphenylphosphine was reacted in a quartz pressure tube at 200° C.with u.v. light initiation until most of the diphenyl phosphine wasconverted. The hot, molten reaction mixture was added to 720 g of hottoluene with stirring. The tetraadduct product precipitated from thesolution as a white crystalline solid. The mixture was allowed to coolto ambient temperature and then filtered with suction. After washingwith toluene and drying in vacuo, 84 g (47.7%) of crude product wasobtained. This was recrystallized from 1200 ml of xylene to obtain 69 gof the pure tetrakis(diphenylphosphinoethyl) silane of mp. 198°-199° C.

Anal. Calcd. for C₅₆ H₅₆ SiP₄ : C, 76.34; H, 6.41; P, 14.06. Found: C,76.44; H, 6.38; P, 13.71.

Similar additions are carried out using di-4-tolyl phosphine anddi-4-fluorophenyl phosphine and the above unsaturated reactants to yieldthe corresponding ring substituted products.

II. Preparation of Tris(Silylalkyl Diaryl Phosphine) Rhodium CarbonylHydride Complexes (Examples 11 to 32)

A. Preparation from Rhodium Chloride

EXAMPLE 11 Tris-(Trimethylsilylethyl Diphenyl Phosphine) RhodiumCarbonyl Hydride

    3Ph.sub.2 PCH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3 +RhCl.sub.3.3H.sub.2 O→[Ph.sub.2 PCH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3 ].sub.3 Rh(CO)H

To a vigorously stirred, refluxing, nitrogenated solution of 11.4 g (40mmole) of tris-(trimethylsilylethyl) diphenyl phosphine of Example 1 in400 ml of ethanol, a hot solution of 1.04 g (0.4 mmole) of rhodiumtrichloride trihydrate in 80 ml ethanol was added at once. After a delayof 15 seconds, 40 ml warm aqueous (37%) formaldehyde solution and,immediately thereafter, 80 ml hot ethanolic solution of 3.2 g ofpotassium hydroxide were added. The resulting clear orange liquidreaction mixture was refluxed for 10 minutes. During the heating, thecolor changed to deep orange.

The mixture was cooled to -25° C. to crystallize the complex product.Crystallization started at -10° C. and was completed on standing forabout 2 hours at -25° C. The crystalline complex was separated byfiltration through a precooled Buechner funnel with suction and washingsuccessively with 20 ml cold portions of ethanol, water, ethanol andn-hexane. The complex was then dried in the presence of anhydrouscalcium chloride at 0.1 mm over the weekend. As a result, 2.2 g (2.2mole, 55%) of dry tri-(trimethylsilylethyl diphenyl phosphine) rhodiumcarbonyl hydride complex was obtained as a fine crystallineorange-yellow powder. In a sealed capillary tube, the complex meltedbetween 126°-129° C. to a clear dark red liquid. In an open capillary,complete melting occurred at 121° C. There was no sign of decompositionon heating up to 140° C. in either case.

The infrared spectrum of the complex in Nujol showed a strong carbonylband of 1985 cm⁻¹ and a band of medium intensity at 1900 cm⁻¹.

Analyses Calcd. for C₅₂ H₇₀ OP₃ RhSi: C, 63.01; H, 7.12; P, 9.38; Found:C, 62.89; H. 7.06; P, 9.59.

B. Preparation from Tris-(Triphenyl Phosphine) Rhodium Carbonyl HydrideVia Ligand Displacement (Examples 10-19).

EXAMPLES 12-22 Tris-(Silylalkyl Diphenyl Phosphine) Rhodium CarbonylHydrides ##STR14##

The tris-(alkyl diaryl phosphine) rhodium carbonyl hydride complexeswere prepared by reacting commercially available tris-(triphenylphosphine) rhodium carbonyl hydride (from Engelhard Minerals andChemicals Corporation, Newark, N.J.) with the corresponding alkyl diarylphosphines. Generally, the reactions were performed in a 90 to 10mixture of toluene and deuterated benzene as a solvent under a nitrogenblanket. The deuterated benzene component was used as a primary nmrstandard.

At first, an about 5% solution of the alkyl diaryl phosphine reactantwas prepared. To samples of the solution, TPP rhodium carbonyl hydridewas added in equivalent and half equivalent amounts. The resultingmixtures were magnetically stirred until homogeneous liquids wereobtained. Additional amounts of the toluene solvent were used if needed.The homogeneous reaction mixture was then studied by ³¹ P nmrspectroscopy. Chemical shifts were measured by assigning a shift of 0ppm to the frequency at which 1M H₃ PO₄ would resonate.

The ³¹ P NMR experiments were carried out using a JEOL FX 90Qmultinuclear nmr spectrometer. When required, the experiementalconditions were adjusted, i.e., the ¹ H-³¹ P decoupling was removed andlonger delays between pulses were employed, to determine the relativepopulations of free and rhodium bound alkyl diphenyl phosphine and TPP.

In general, three and six moles of a silylalkyl diphenyl phosphine wereused per mole of tris TPP rhodium carbonyl hydride. ³¹ P NMRspectroscopy of the resulting solutions showed that the added liganddisplaced the TPP. The doublet signal of the bound TPP essentiallydisappeared and the singlet signal of free TPP appeared instead. In themixtures having 3 moles of the added silylalkyl phosphine, most of theadded ligand was bound and as such exhibited a doublet signal upfieldfrom that of bound TPP. Although the doublet of the silylalkyl diphenylphosphine complexes have chemical shift values different from that ofTPP, the coupling constants are about the same for both types ofcomplexes. The coupling constant and chemical shift difference betweenbound and free ligand indicates that both types of ligands formtris-phosphine rhodium carbonyl hydrides. Finally, it was noted that themixture having six moles of added alkyl diphenyl phosphine ligand hadabout equal amounts of free and bound ligand plus the originally boundTPP as additional free ligand.

The nmr parameters of the trihydrocarbylsilylalkyl diphenyl phosphinecomplexes are shown by Table II (Examples 11-19). The mostcharacteristic parameter is the chemical shift value of the rhodiumcomplexed ligand. For comparison, the chemical shift values of the freeligands are also tabulated. Complexation by rhodium of the phosphineapparently produced a similar downfield change of the shift values.Finally, it is also noted in reference to the table, that even thelimited exposure of the rhodium complexed phosphines to air resulted insome oxidation to the corresponding phosphine oxides. The latterexhibited sharp singlets slightly upfield from the complexed phosphine,in general.

The data of Table II show that, with the exception of the sixth compoundall the phosphine ligands form similar, well characterizable complexesat room temperature. The line shapes of the signals showed little butvarying broadening, i.e., ligand exchange.

The ³¹ P nmr parameters were similarly determined for the rhodiumcomplexes of triethylsilylethyl diphenyl phosphine,tris-(diphenylphosphinoethyl) methyl silane andtetrakis-(diphenylphosphinoethyl) silane. The monophosphine complexexhibited a simple doublet of σ34.7 ppm and J P-Rh of 151 cps. Thetris-phosphine complex showed a more complex signal of what appeared tobe two doublets having chemical shifts of 35.3 and 36.8 ppm andidentical coupling constants of 154 cps. Finally, the tetraphosphinecomplex gave an even more complex signal, apparently consisting of threedoublets, having the following chemical shift values and couplingconstants: 37.6 (154); 37.0 (151) and 35.9 (149) [Examples 21 and 22].

Example 23 Mixed Tris-Phosphine Rhodium Carbonyl Hydride Complex Speciesin TPP and/or SEP Based Catalyst Systems ##STR15##

                                      TABLE II                                    __________________________________________________________________________    .sup.31 P Nuclear Magnetic Resonance Parameters of Free and                   Rhodium-Complexed Trihydrocarbylsilylalkyl Diphenyl Phosphines                                                          Coupling                                                                            Chemical                                                                            Chemical Shift                                         Chemical Shift                                                                           Constant,                                                                           Shift Difference              Example                                                                            Example                   δ, ppm                                                                             P--Rh δ,                                                                            Δδ,                                                               ppm                     No. of                                                                             No. of                    Free Complexed                                                                           Complexed                                                                           Phosphine                                                                           Complex                 Complex                                                                            Ligand                                                                             Chemical Structure of Complex                                                                      Ligand                                                                             Ligand                                                                              Ligand                                                                              Oxide Ligand                  __________________________________________________________________________    --   --   (Ph.sub.3 P).sub.3 Rh(CO)H(Reference)                                                              -7.5 +38.3 155         45.8                    13   1    [Ph.sub.2 PCH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3 ].sub.3                                            -12.2)H                                                                            +34.6 150   +27.0 46.7                    14   2    [Ph.sub.2 PCH.sub.2 CH.sub.2 Si(C.sub.3 H.sub.7).sub.3 ].sub.3                Rh(CO)H              -11.2                                                                              +34.8 151   +29.9 46.0                    15   3    (Ph.sub.2 PCH.sub.2 CH.sub.2 SiPh.sub.3).sub.3 Rh(CO)H                                             -10.6                                                                              +35.5 151   +21.1 46.1                    16   4    [(Ph.sub.2 PCH.sub.2 CH.sub.2).sub.2 Si(CH.sub.3).sub.2 ].sub.3               [Rh(CO)H]            -12.2                                                                              +35.1 150   +27.2 47.3                    17   5    [Ph.sub.2 PCH.sub.2 CH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3                      ].sub.3 Rh(CO)H      -19.7                                                                              +26.6 154   +24.6 46.3                    18   6    (Ph.sub.2 PCH.sub.2 Si(CH.sub.3).sub.3 ].sub.3 Rh(CO)H                                             -24.4                                                                              +17.0 .sup. 133.sup.a                                                                     +23.9 41.4                    19   7    [(Ph.sub.2 PCH.sub.2 CH.sub.2 CH.sub.2).sub.2 Si(CH.sub.3).sub.2               ].sub.3 Rh(CO)H     19.5 26.5  156         46.2                    20   8    [(Ph.sub.2 PCH.sub.2 CH.sub.2).sub.2 SiPh.sub.2 ].sub.3                                            -11.6)H                                                                            35.3  151    27.2 46.9                    __________________________________________________________________________     .sup.a The .sup.31 P--.sup.103 Rh coupling was not resolved at room           temperature but was clearly resolved at -60° C.                   

As it is illustrated by the above reaction scheme, the displacement ofthe triaryl phosphine ligands from their tris-phosphine rhodium carbonylhydride complexes in a stepwise reaction. The scheme indicates that 2"mixed phosphine complexes" are intermediates in such displacements.Each of these complexes should exhibit two doublet ³¹ P nmr peaks withfurther P-P splitting.

Starting with the tris-TPP complex, experiments were carried out withvarying amounts of the SEP ligand to determine what ranges of SEP/TPPratios will result in major amounts of mixed complexes. These studieswere carried out in the manner described in the previous example.However, to slow down ligand exchange they were carried out at -60° C.This should improve the detection of minor complex species. The resultsare illustrated by FIG. 2.

For reference, FIG. 2 shows the ³¹ P nmr spectra of the TPP and SEPcomplexes in the presence of a three-fold molar excess of TPP and SEP,respectively. These spectra are to be compared with that of two mixturescontaining a low and a high ratio of SEP to TPP.

The first mixture contained 2 moles of SEP and 3 moles of TPP perrhodium. Its spectrum has shown that, nevertheless, the tris-SEP complexwas a primary component. There are four other major doublets in thecomplex spectrum of this mixture. These are apparently due to the twomixed phosphine complexes. It is interesting to observe that there areno significant amounts of the TPP complex present. Accordingly, thereare major amounts of the free TPP and minor amounts of the free SEPligand. As it is indicated by the line broadening of the free SEP peak,the ligand undergoes a fast ligand exchange with the mixed complexes,even at -60°, i.e., faster than TPP.

The second mixture contained 60 moles of SEP ligand per 30 moles of TPPand one atom of Rh. This means a SEP to TPP ratio of 20. At this highratio, only the doublet signal of the tris-SEP complex is exhibited. Allthe triphenyl phosphine shows up as being free. Its extremely narrowpeak indicates that there is essentially no participation by TPP in theligand exchange process.

Example 24 Comparative Rates of the Formation of bis-TPP and bis-SEPRhodium Carbonyl Hydrides Via the Thermal Dissociation of TheirRespective Tris-Phosphine Complexes

In the case of the tris-(trimethylsilylethyl diphenyl phosphine),tris-SEP, rhodium carbonyl hydride complex, there was moderately slowligand exchange between free and complexed phosphines as indicated bythe broadening of the ³¹ nmr signals. The exchange mechanism isillustrated for the SEP complex by the following: ##STR16## as indicatedby this mechanism the exchange rates are directly related to the rate ofthe dissociation of the tris-phosphine complex.

The line shapes of signals for the SEP complex and the known TPP complexare compared by FIG. 3 at various temperatures. At first, the 30° C.spectra will be discussed. These spectra indicate that at 30° C., thereis a similar, ligand exchange rate between the new SEP and the known TPPcomplex.

The tris-SEP complex and most of the other trihydrocarbylsilylethyldiphenyl phosphine complexes showed a very similar ligand exchangebehavior at 30° C. The tripropylsilylethyl diphenyl phosphine complex(Example 12) exhibited a definitely slower exchange rate. The exchangerate of the triphenylsilylethyl diphenyl phosphine complex (Example 13)was even much slower than that. It appeared that substituted alkyldiphenyl phosphine ligands of increasing bulkiness had decreasing ligandexchange rates. In both cases though, the TPP ligand exchanged lessrapidly than the alkyl diphenyl phosphine.

Finally, it is noted that when even a moderately bulky alkylsubstitutent was too close to the phosphorus, i.e., in the case oftrimethylsilylmethyl diphenyl phosphine, the complexation of phosphorusto the rhodium was inhibited. In that case, there was no distinctcomplex formation with the sterically hindered ligand at 30° C. At -60°C., a stable complex was formed. However, this complex was decomposedwhen its solution was heated under hydroformylation process conditions.

As far as ligand exchange rates at higher temperature are concerned, theresults shown by FIG. 3 are typical. FIG. 3 shows the comparison of twosystems: tris-triphenyl phosphine rhodium carbonyl hydride plustriphenyl phosphine and tris-trimethylsilylethyl diphenyl phosphine plustriphenyl phosphine. The latter system is the result of equilibratingthe TPP complex with trimethylsilylethyl diphenyl phosphine (SEP):##STR17## SEP being a substituted alkyl diphenyl phosphine, was found tobe a stronger complexing agent than TPP. The spectra of both systemswere taken under comparative conditions at 30°, 60° and 90° C.

The line shapes of the signals of the 30° spectra showed little signalbroadening in both cases. This indicated comparably slow exchange ratesof about 25 per second. In alternative terms, relatively long averageexchange lifetimes, in the order of 2×10⁻² sec, were indicated for bothtriphosphine complexes. At 60°, considerable line broadening occurred,indicating a much faster exchange. The exchange acceleration was greaterin the case of the TPP system (k=600 vs. 80 sec⁻¹). The average lifetimewas about 3×10⁻³ sec for the TPP system and 6×10⁻³ sec for the SEPsystem. At 90°, only a single, broad signal could be observed for theTPP system while the SEP system still exhibited separate, althoughextremely broad, chemical shift ranges for the complexes and freephosphorus species. Apparently, the exchange acceleration in the case ofthe PP system was tremendous. The average lifetime between exchanges wasreduced by about two orders of magnitude to 5×10⁻⁵ sec (k=10,000 sec⁻¹).In the case of the SEP system, the average lifetime dropped by about oneorder to 5×10⁻⁴ sec (k= 1,500 sec⁻¹). It must be emphasized that theexchange rates and lifetimes reported here may change somewhat when thelineshape is subjected to a rigorous computer analysis. The relativeorder of their values will remain unaltered, however.

It is interesting to note that there was no great change of equilibriawith the increasing exchange rates. Apparently, both ligand eliminationand addition increase similarly in this temperature range. Thetris-phosphine rhodium species remained the dominant form of complexes.In the SEP complex plus free TPP system, the rhodium remainedpredominantly complexed to the SEP.

The role of excess phosphine ligand is apparently to maintain theequilibria in favor of the tris-phosphine complex, i.e. to reduce boththe concentration and average lifetime of the unstable and highlyreactive bisphosphine complex. The increased ligand exchange rateprovides enough active bis-phosphine complex catalytic species for fasthydroformylation, without leading to noncatalytic side reactions, i.e.,catalyst decomposition.

In summary, the above and similar ligand exchange rate studies indicatethat, in the presence of excess ligand, the silyl alkyl diaryl phosphinerhodium complexes are catalytically activated at higher temperaturesthan the known triaryl phosphine rhodium complexes. Less ligand exchangeat comparable temperature also meant a higher temperature for theirreversible thermal dissociation, i.e., decomposition of the catalystcomplex.

C. Preparation from Dicarbonyl Acetylacetonato Rhodium Via LigandDisplacement and Hydrogenation

For the isolation of pure complexes, one usually starts with an about0.8% ethanolic solution of the dicarbonyl acetonato rhodium startingcompound. Then a threefold molar excess of the phosphine ligand inslight excess is added to provide a solution of the intermediatecomplex. This is then reduced by hydrogen. The complex is usually formedas a precipitate.

Example 25 Tris-(Trimethylsilylethyl Diphenyl Phosphine) RhodiumCarbonyl Hydride ##STR18##

To a magnetically stirred solution of 0.258 g (0.01 mole) dicarbonylacetylacetonato rhodium in ethanol, 0.887 g (0.0031 mole) oftrimethylsilylethyl diphenyl phosphine was added under nitrogen.Instantaneous displacement of one of the carbonyl ligands was indicatedby the evolution of CO gas. The resulting dark orange solution of theintermediate was transferred to a glass pressure tube equipped with aTeflon screw valve and a magnetic stirrer, for hydrogenation.

The reaction tube was evacuated until the solvent started to boil. Thenit was filled and pressured with hydrogen to a pressure of about 2 Atm.

On stirring the reaction mixture, rapid hydrogenation occurred. Thecolor of the solution started to become lighter. After an hour, yellowcrystalline solids started to precipitate. The reaction mixture wasstirred overnight under hydrogen pressure to complete the reduction. Thehydrogen was then released and the mixture was filtered with suctionunder nitrogen. A light orange filtrate and yellow crystals wereobtained.

The crystals were washed twice with 2 ml portions of ethanol and driedunder a pressure of 0.1 mm and at room temperature. The resulting puretris-SEP rhodium carbonyl hydride was 0.65 g, i.e., about 65% of thetheoretical yield. Its solid state ³¹ P nmr spectrum supported theexpected structure.

The ³¹ P nmr spectrum of the combined filtrates showed that essentiallyall the phosphorus was in the form of the same tris-SEP complex. Thisindicated that the reaction was quantitative.

The tris-SEP complex was also formed in aromatic hydrocarbon andaldehyde solvents. Hydrogen could be effectively used for reduction atatmospheric pressure. The reaction was complete within a few hours inaromatic hydrocarbons.

EXAMPLES 26-30 Other Tris-(Silyalkyl Diphenyl Phosphine) RhodiumCarbonyl Hydrides

In a manner similar to the SEP complex preparation described in theprevious example, analogous complexes of other silylalkyl diphenylphosphines were obtained. The trimethylsilylpropyl diphenyl phosphinecomplex formed a crystalline precipitate. The two bis(diphenylphosphinoalkyl) silane complexes were oily. The tripropylsilylethyl andtriphenylsilylethyl diphenyl phosphine complexes remained in solutionwhen this procedure was used. On removing the ethanol in vacuo, oilycomplexes were obtained.

EXAMPLE 31 Mixed Tris-Phosphine Rhodium Carbonyl Hydride Complex Speciesin Octyl Diphenyl Phosphine and SEP Based Catalyst Systems

Complex equilibria can be studied by ³¹ P nmr between different alkyldiaryl phosphine complexes via the hydrogenation of their mixtures withdicarbonyl acetylacetonato rhodium. Typically, 3 moles of each of twophosphine ligands are used per mole dicarbonyl acetylacetonato rhodium.The rhodium reactant is used in amounts corresponding to 2 weightpercent of the solvent, typically a 9/1 mixture of toluene anddeuterobenzene. The phosphine reactants are then added to prepare asolution of the intermediate. This solution is then placed into apressure tube equipped with a Teflon valve. This tube, properly shapedand fitted doubles as a reactor and an nmr sample container. It ispressured by hydrogen to 30 psi, i.e., about 2 atm. Then it is shaken,usually overnight. This results in the formation of tris-phosphinerhodium carbonyl hydride complexes plus 3 moles of free phosphine. Ifthe binding strength of the two phosphines is equal, a statisticaldistribution results between the four potential complexes as indicated:##STR19## Such a distribution was the approximate result of thecompetition between the SEP ligand [R=(CH₃)₃ SiCH₂ CH₂ ] and n-octyldiphenyl phosphine [R=CH₂ (CH₇)]. The signals of the two free ligandswere of equal intensity. The relative amounts of the free phosphineligands are usually in a simple indirect relationship to the strength ofcomplexation with the rhodium.

EXAMPLE 32 Tris-t-Phosphine Rhodium Carbonyl Hydride Equilibria at HighP/Rh Ratios Among SEP and Ar₃ P Complexes

Using the ³¹ P nmr technique of the previous example, equilibria amongtris-SEP rhodium carbonyl hydride and complexes including one or moretriaryl phosphine ligands were also studied at high P/Rh ratios. Rh toSEP to Ar₃ P ratios of 1:20:80 were used in the absence of added solventwith TPP and 4-chlorophenyl diphenyl phosphine (Cl-TPP) as the Ar₃ Pligand. Cl-TPP was employed because of its relatively low mp. (45° C.).

The results of these variable temperature experiments showed that, dueto the fairly high SEP/Rh ratio, complexes containing SEP predominated,even though the Ar₃ P/Rh ratio was much higher. Substituted triarylphosphine components were preferred because of their generally highersolubility.

EXAMPLE 33 Bis-(Trimethylsilylethyl Diphenyl Phosphine) Rhodium CarbonylHydride and Excess Ligand Coordinated with n-Valeraldehyde

Complex equilibria with coordinating solvents can be also established atdifferent concentrations and temperatures. Interactions with aldehydesare particularly important since the aldehyde products are alwayspresent in the hydroformylation mixtures. Comparative low temperture ³¹P nmr studies of tris-(alkyl diaryl phosphine) rhodium carbonyl hydridesolutions in aromatic hydrocarbons and valeraldehyde have shown thatvaleraldehyde facilitates the dissociation of tris-phosphine complexesand the formation in turn of carbonyl dimer derivatives of thebis-phosphine complex. Under hydrogen pressure, the latter is inequilibrium with the trisphosphine complex. Aldehydes appear importantin the stabilization of the key active intermediate, the coordinativelyunsaturated trans-bis-(alkyl diaryl phosphine) rhodium carbonyl hydride,e.g., the bis-SEP complex,

    [Ph.sub.2 PCH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3 ].sub.2 Rh(CO)H

EXAMPLE 34 Trimethylsilylethyl Diphenyl Phosphine Rhodium DicarbonylComplexes

Complex equilibria between various catalytic intermediates derived fromtrans-bis-phosphine carbonyl hydride could be also studied via similarmethods in the presence of varying amounts of excess phosphine ligand.The results of these studies contrast the behavior of the SEP and TPPcomplexes toward CO and show the influence of excess phosphine ligand instabilizing the desired catalyst structures.

When solutions of the tris-phosphine rhodium carbonyl hydride complexesand excess phosphine were placed under pressure of CO and varyingmixtures of H₂ and CO rapid ligand exchange and the formation ofbis-carbonyl complexes leading to non-selective hydroformylation wereobserved. At low temperature, the rate of the ligand exchange wasdecreased and the ³¹ P doublet signals originating from severaldifferent rhodium complexes, including the tris-phosphine rhodiumcarbonyl hydride and bis-phosphine rhodium dicarbonyl hydride, could beobserved. It was noted that the ratio of the monocarbonyl complexes tothe dicarbonyl complexes increased with increasing H₂ /CO and P/Rhratios. Under comparable conditions less of the undesired dicarbonylcomplex was formed in the SEP system than in the TPP system. Also, thedicarbonyl SEP complex were converted back to the monocarbonyl complexmore readily than the dicarbonyl TPP complex.

The experiments have shown that in the catalyst systems for selectivehydroformylation. The concentration of the tris-phosphine rhodiumcarbonyl hydride is optimized. This complex then acts as a dynamic,stabilizer reservoir and source of the active trans-bis-phosphinecarbonyl hydride. The latter is highly reactive in a reversible mannertoward olefins as it is indicated by the increased ligand exchange underethylene pressure.

III. Preparation of Tris-Silylalkyl Diphenyl Phosphine Complexes ofOther Transition Metals

The novel silyl substituted alkyl diphenyl phosphine complexes of othertransition metals can be prepared via known methods which are developedto prepare triaryl or trialkyl phosphine complexes. A method discoveredduring the course of the present work starts with the readily availabletriphenyl phosphine complexes of transition metals to prepare thecorresponding complexes of silylalkyl diphenyl phosphines via ligandexchange.

EXAMPLE 35 Tris-(Trimethylsilylethyl Diphenyl Phosphine) IridiumCarbonyl Hydride ##STR20##

Tris-(triphenyl phosphine) iridium carbonyl hydride was reacted with theSEP ligand in the manner described in Example 11 to 19. ³¹ P nmrspectroscopy of the liquid reaction mixture indicated that the singletsignal of the TPP complex reactant at 12.4 ppm mostly disappeared and anintense signal for the liberated TPP appeared instead. The formation ofthe SEP complex was shown by the intense new singlet having a chemicalshift value of 10.4 ppm.

EXAMPLE 35A Trimethylsilylethyl Diphenyl Phosphine Cobalt TricarbonylDimer ##STR21##

The cobalt tricarbonyl dimer of TPP was reacted with SEP to yield thedesired product of ligand exchange.

IV. Testing of Tris-(Silyl Alkyl Diaryl Phosphine) Rhodium Complex BasedHydroformylation Catalyst Systems

A. General method of Hydroformylation

The hydroformylation of butene-1 to provide linear pentanal and branched2-methyl butanal products was selected for comparative studies of thecatalytic properties of alkyl diaryl phosphine) rhodium carbonyl hydridecomplexes. The complexes studied were either isolated before use orgenerated in situ. In some cases, the desired complex was generated fromthe known tris(triphenyl phosphine) rhodium carbonyl hydride by theaddition of the appropriate ligand in varying amounts. According toanother standard method, dicarbonyl acetylacetonato rhodium and theappropriate alkyl diaryl phosphine were used as catalyst precursors. Inthat case, the desired rhodium carbonyl hydride complex was generated byhydrogenation during the hydroformylation experiment. Tris-triphenylphosphine rhodium carbonyl hydride in the presence of varying excess oftriphenyl phosphine was used as a known catalyst standard forcomparison.

The experiments were carried out in a 300 ml stainless steel (S) and a300 ml Hastelloy (H) autoclave, respectively. Both autoclaves wereequipped with identical highly effective, impeller type stirrers,operating at 1500 rpm during the experimental runs. The other standardautoclave instrumentation was identical for both units. However, aslightly lower normal to iso aldehyde product ratio (n/i) was observedin unit H. In those cases where the type of autoclave was not specified,a stainless steel unit was used.

The standard batch hydroformylation procedure was the following: theappropriate amounts of rhodium complex were dissolved in 80 g of theproper mixture of free phosphine and solvent. 2-Propylheptyl valerate or2-ethylhexyl acetate were generally used as standard solvents. Mostoften, the amount of complex employed provided 100 ppm rhodiumconcentration. This meant 100 mg, i.e., about 0.1 mole, rhodium per 100g. Accordingly, 100 mg per kg, about 1 mmole per kg rhodium would bepresent in 1 kg starting mixture. The excess ligand added to the solventwas usually calculated to provide a ligand to rhodium ratio (L/Rh) ofabout 140.

The 100 g rhodium complex-ligand solution was placed into the autoclavewhich was then deaerated by repeated pressurization with nitrogen. Thesolution under atmospheric nitrogen pressure was then sealed and heatedto the reaction temperature, usually 100° C.

When the solution reached 100°, 20 g liquid butene was pressured intothe autoclave with a 1 to 4 carbon monoxide-hydrogen initial gasmixture. The butene was followed by the CO/H₂ mixture until a pressureof 350 psig was reached. At that point, the supply of 1:4 to 1:5 CO/H₂was shut off and the autoclave was connected to a cylinder of about 1liter volume containing an about 1:1 CO/H₂ feed gas mixture at 1000psig. The connection was made through a pressure regulating valve set toprovide the 1:1 CO/H₂ gas to the autoclave to maintain a 350 psigpressure during the reaction. The exact H₂ /CO ratio of the feed gas wasoften varied to maintain the initial H₂ /CO ratio in the autoclave. Thereaction was typically run to an 80% conversion on the basis of the H₂/CO consumed.

In the standard tests, the autoclaves used were equipped with synthesisgas feed lines adjoining the autoclave above the Magnedrive stirredassembly unit (FIG. 4). It is to be noted that this manner ofintroducing synthesis gas feed far from the upper level of the liquidreaction mixture (Method A) resulted in an incomplete equilibration ofthe synthesis gas mixture between the gas and liquid phase. Particularlyin those cases where the initial synthesis gas mixture (used to pressureup the reaction mixture) had a H₂ to CO ratio of 10 or higher, the COcomponent of the subsequent one to one feed gas was not effectivelydelivered from the top into the liquid reaction mixture due to masstransfer limitations. Therefore, the reaction mixture was often"starved" of CO during the early fast phase of the reaction. As aconsequence, the H₂ /CO ratio in the liquid temporarily rose to veryhigh values. This resulted in particularly high n- to i-aldehyde productratios. Also, olefin hydrogenation and isomerization became importantside reactions. For comparison, the widely studied tris-TPP rhodiumcarbonyl hydride catalyst system was used as a standard throughout thework. Generally, the reaction was run to an 80% conversion on the basisof the H₂ /CO consumed when using this method.

In those instances where the effect of H₂ to CO ratios and the effect ofCO partial pressure were especially studied, the synthesis gas feed wasintroduced at the side of the autoclave through a side arm just abovethe liquid level (FIG. 4, Method B). This method of operation largelyavoided any temporary rise of H₂ /CO ratios and drastically reducedhydrogenation and isomerization in cases where the initial H₂ /CO ratiowas high.

In the third method of operation, the synthesis gas was introduced intothe liquid reaction mixture at the bottom, close to the stirrer througha sintered inductor to assure small bubble size and instantaneous mixing(FIG. 4, Method C). This method was the best for avoiding higher thanequilibrium H₂ /CO ratios during the reaction. As such the method gavethe smallest n/i ratios of isomeric aldehyde products and the leasthydrogenation and isomerization of the olefin, i.e., the highestselectivity for total, i.e., n+i, aldehyde products. Using this method,the reaction was usually run to 50% conversion on the basis of theconsumed synthesis gas. Special studies were also made in a continuousfeed introduction and product flashoff operation. This allowed acontinuous control of partial pressures and such provided the mostaccurate results.

The progress of the hydroformylation was followed on the basis of theamount of 1:1 CO/H₂ consumed. The latter was calculated on the basis ofthe pressure drop in the 1 liter CO/H₂ cylinder. Reactant conversioncalculated on the basis of CO consumption was plotted against thereaction time to determine the reaction rate. The reaction rate wasexpressed as the fraction of the theoretical CO/H₂ requirement consumedper minute (k min⁻¹). The reaction was discontinued when the reactionrate drastically dropped. Dependent on the side reaction, such asbutene-1 hydrogenation and butene-1 to butene-2 isomerization, thereaction temperature and the stability of the catalyst complex in themixture, such a rate drop occurred generally between 80-98% COconversion.

When the reaction was to be discontinued, the CO/H₂ feed valve was shutand the autoclave was immediately cooled with cool water. In case of lowconversions, ice bath was used. When cooling was complete, the synthesisgas was released slowly. The residual liquid was visually observed forcatalyst decomposition. A dark orange to brown color of the originallyyellow mixture indicated increasing degrees of catalyst decomposition.Severe catalyst decomposition usually resulted in the precipitation ofdark solids.

Analyses of the residual liquid mixture were carried out using gaschromatography. The liquids were analyzed in a gc instrument using flameionization detector. By this instrument, the C₄ hydrocarbons weredetected. Due to the lower response of this detector to the aldehydes,the intensity of the hydrocarbon peaks was multiplied usually by 0.7 toobtain the necessary concentration correction. The individual, gaseousC₄ hydrocarbons were separated by another chromatograph. At first, thesegases were separated from the liquids and then the individual componentsof the gas were chromatographed and detected by a thermal conductivitydetector.

B. 1-Butene Hydroformylation (Examples 36-43)

The following description of 1-butene hydroformylation catalysis will beexemplified by a detailed description of the tris-(trimethylsilylethyldiphenyl phosphine) rhodium carbonyl hydride, i.e., SEP complex, plusSEP system. For comparison, detailed data will also be provided on theknown tris-(triphenyl phosphine) rhodium carbonyl hydride, i.e., TPPcomplex, plus TPP system. For comparison, detailed data is also providedon the known tris-(triphenyl phosphine) rhodium carbonyl hydride, i.e.,TPP complex plus TPP, system. It is noted that Method A, introducing thesynthesis gas feed at the top of the reactor assembly, was used inseveral Examples as indicated hereafter. Consequently, CO starvation didoccur at high reaction rates and these data are not available fordetermining physicochemical constants, such as activation energies.

EXAMPLE 36 Tris-(Trimethylsilylethyl Diphenyl Phosphine) RhodiumCarbonyl Hydride as a Catalyst in the Presence of 140-Fold Ligand Excessat Different Temperatures

The complex of Example 10 was studied at the 107 ppm rhodium level inthe presence of 140-fold (0.14 M) trimethylsilylethyl diphenyl phosphine(SEP) ligand as a butene hydroformylation catalyst using the generalprocedure describe above for Method A. Comparative experiments were runusing 107 ppm rhodium as a tris(triphenyl phosphine) carbonyl hydridecomplex with 140-fold triphenyl phosphine (TPP). Reaction rates, n/iproduct ratios, conversions and byproducts were determined at varioustemperatures. The results are shown by Table III.

The data of the table show that both the SEP and the TPP based catalystsystems are highly active and produce a high ratio of n/i products atmost temperatures. However, the temperature dependence of the twosystems is very different. The procedure used in the runs was that ofMethod A.

                                      TABLE III                                   __________________________________________________________________________    HYDROFORMYLATION AT DIFFERENT TEMPERATURES                                                Feed:  Butene-1 and 1:4 CO/H.sub.2 at 350 psi                                 Catalyst:                                                                            L.sub.3 Rh(CO)H, Rh 107 ppm, Rh/L = 140                                SEP Ligand:                                                                          (CH.sub.3).sub.3 SiCH.sub.2 CH.sub.2 Pφ.sub.2 TPP                         Ligand: φ.sub.3 P                                      Variable Conditions                                                                        Reaction Rates and Selectivities                                 of Catalysis                         By-Product,                                                                            Details                                 Reaction                                                                           Fraction of                                                                           Product                                                                            Reaction                                                                           Butene                                                                              Mole % in                                                                              Exact                           Seq.                                                                             Catalyst                                                                           Temp.,                                                                             CO/H.sub.2 Reacted                                                                    n/i  Time Conversion                                                                          Product Mixture                                                                        Rh Conc.                        No.                                                                              Ligand                                                                             °C.                                                                         k, min.sup.-1                                                                         Ratio                                                                              Min. %     Butane                                                                            Butene-2                                                                           ppm                             __________________________________________________________________________    1  SEP  100  0.03    6.1  35   86.9  2.0 3.8  106                             2       120  0.10    6.2  35   96.5  9.4 6.2  106                             3       140  0.21    5.7  15   97.5  14.5                                                                              12.4 108                             4       145  0.27    5.0  15   95.2  11.9                                                                              12.1 109                             5  TTP  100  0.21    7.5  35   98.9  10.7                                                                              12.1 107                             6       120  0.34    5.9  10   97.3  9.3 12.2 104                             7       140  0.38    3.4  10   98.2  11.2                                                                              21.9 105                             8       145  0.27    2.4  15   97.7  11.9                                                                              26.0 103                             __________________________________________________________________________

The novel SEP catalyst system exhibits an increasing activity withelevated temperatures. At 100° and 120° the n/i ratio of products isabout the same and there is only a small n/i drop at 145°. High buteneconversion is observed at all temperatures. The only adverse effect oftemperature increase is the increased hyrogenation and isomerization ofthe butene-1 reactant. The SEP system remains clear, bright yellow inappearance, even at 145°.

The known TPP catalyst system exhibits the same increased activity at120° and 140°. However, the n/i ratios in this case are monotonouslyreduced with increasing temperatures. At 145°, the n/i ratio of productsis significantly lower in the TPP than in the SEP system. At 145°, thereaction rate of the TPP system also drops. Decomposition of this systemat this temperature is indicated by darkening of the reaction mixture.

EXAMPLE 37 Tris-(Trimethylsilylethyl Diphenyl Phosphine) RhodiumCarbonyl Hydride Complex as a Catalyst in the Presence of 1 M ExcessLigand at Different Temperatures

The SEP-rhodium complex catalyst system and the correspondingTPP-rhodium systems were also compared as butene hydroformylationcatalysts using Method C. This comparison was made in considerabledetail of systems containing a high excess, i.e., 1 molal concentrationof excess ligand in the starting reaction mixture. Data were obtained attemperatures ranging from 100°-160° C. The results are shown in TableIV.

To assess the effect of changing the experimental procedure from MethodA to C, Table IV also shows some data at 0.14 M excess ligandconcentration (Seq. Nos. 1, 2 and 8). This ligand concentration waswidely used in the previous examples with Method A. The comparison withTable III shows that the use of Method C results

                                      TABLE IV                                    __________________________________________________________________________    Hydroformylation of 1-Butene with Tris-Phosphine Rhodium Carbonyl             Hydride                                                                       Catalyst Using Ph.sub.2 PCH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3 (DTS) or        Ph.sub.3 P (TPP)                                                              Reactions at 350 psi (24.7 atm) of 5/1 H.sub.2 /CO with 20 g 1-butene and     80 g of phosphine plus 2-ethylhexyl                                           acetate solvent, using AcacRh(CO).sub.2 as catalyst precursor and             introducing the feed gas into the stirred                                     reaction mixture.                                                                                      H.sub.2 /CO Consumption         By-product                                    Dependent Factors                                                                          Aldehyde Product Parameters                                                                      Selectivity,         Catalyst System Parameters                                                                             (50% Conversion)                                                                           Linearity                                                                              Hydroformylation                                                                        %                    Experiment                                                                              M in                                                                              Rh     Feed                                                                              H.sub.2 /                                                                        Rate Reaction n × 100                                                                      Selectivity                                                                             2-                   Seq.                                                                             Run                                                                              Temp.                                                                             Mix at                                                                            Conc.                                                                             P.sup.b /                                                                        Ratio                                                                             CO Constant                                                                           Time n/i n + i                                                                              n + i                                                                             n- i- Bu-                                                                              Bu-               No.                                                                              No.                                                                              °C.                                                                        start                                                                             m--M                                                                              Rh H.sub.2 /CO                                                                       Final                                                                            k, min.sup.-1                                                                      min. Ratio                                                                             %    %   %  %  tenes                                                                            tanes             __________________________________________________________________________    DTS                                                                           1  245                                                                              145 0.14                                                                              0.25                                                                               560                                                                             54/46                                                                             5.9                                                                              0.083                                                                              8.5  4.9 82.9 89.8                                                                              74.5                                                                             15.3                                                                             6.8                                                                              3.5               2  246                                                                              145 0.14                                                                              0.10                                                                               140                                                                             54/46                                                                             5.5                                                                              0.035                                                                              19   4.6 82.2 90.7                                                                              74.6                                                                             16.1                                                                             6.5                                                                              2.8               3  249                                                                              110 1.0 4.0  250                                                                             52/48                                                                             4.9                                                                              0.032                                                                              22   7.6 88.4 93.9                                                                              83.0                                                                             10.9                                                                             4.3                                                                              1.8               4  142                                                                              125 1.0 1.0 1000                                                                             52/48                                                                             4.6                                                                              0.026                                                                              27   8.2 89.1 94.1                                                                              83.8                                                                             10.2                                                                             4.0                                                                              1.9               5  138                                                                              135 1.0 1.0 1000                                                                             53/47                                                                             5.1                                                                              0.046                                                                              15   9.8 90.8 90.2                                                                              81.9                                                                             8.3                                                                              5.9                                                                              3.9               6  101                                                                              145 1.0 1.0 1000                                                                             54/46                                                                             6.9                                                                              0.073                                                                              10   11.4                                                                              91.9 89.3                                                                              82.1                                                                             7.2                                                                              6.8                                                                              3.9               7  247                                                                              160 1.0 0.5 2000                                                                             56/44                                                                             6.9                                                                              0.065                                                                              11   11.3                                                                              91.9 82.8                                                                              76.1                                                                             6.7                                                                              10.8                                                                             6.4               TPP                                                                           8  171                                                                              145 0.14                                                                              0.05                                                                               280                                                                             54/46                                                                             5.8                                                                              0.040                                                                              18   4.1 80.2 83.0                                                                              66.6                                                                             16.5                                                                             13.4                                                                             3.5               9  135                                                                              110 1.0 0.5 2000                                                                             52/48                                                                             5.1                                                                              0.017                                                                              40   13.0                                                                              92.8 91.3                                                                              84.7                                                                             6.5                                                                              5.7                                                                              3.0               10 130                                                                              125 1.0 0.5 2000                                                                             52/48                                                                             4.7                                                                              0.058                                                                              12   11.9                                                                              92.3 89.1                                                                              82.2                                                                             6.9                                                                              7.9                                                                              3.1               11 129                                                                              135 1.0 0.5 2000                                                                             54/46                                                                             6.5                                                                              0.078                                                                              9    12.8                                                                              92.7 84.2                                                                              78.1                                                                             6.1                                                                              10.7                                                                             5.1               12 128                                                                              145 1.0 0.5 2000                                                                             54/46                                                                             5.4                                                                              0.104                                                                              7    10.7                                                                              91.5 80.4                                                                              73.6                                                                             6.9                                                                              13.2                                                                             6.4               13 144                                                                              160 1.0 0.25                                                                              4000                                                                             56/44                                                                             5.6                                                                              0.064                                                                              11   7.6 88.4 78.9                                                                              69.7                                                                             9.2                                                                              15.8                                                                             5.3               __________________________________________________________________________

in a lower n/i ratio of aldehydes but a higher n+i aldehyde selectivity,i.e., lower by-product formation.

In general, the use of the high 1 M, ligand excess increased both then/i ratio and the n+i selectivity in both the SEP and TPP systems at alltemperatures (Seq. Nos. 3 to 7 and 9 to 13). The use of the SEP systemalways resulted in a somewhat higher total aldehyde selectivity.However, in the 145°-160° C. range, the selectivity of the SEP systemwas considerably better, apparently due to its increased thermalstability. The n/i ratio of the aldehydes produced in the SEP catalyzedreaction was even slightly increased as the temperature was raised from110° to 145° C. This was probably due to the reduced CO concentrationsin the liquid reaction mixture at increased temperatures.

The general lesser total (n+i) aldehyde selectivity of the TPP system ismainly due to the significant isomerization of the 1-butene reactant to2-butenes at 160° C., the n/i ratio of the aldehydes is also decreasedgreatly in the TPP system. At this temperature, the TPP catalyst systemis basically changed, although no gross instability could be observedduring the short reaction period. The behavior of the SEP and TPPsystems is compared by FIGS. 5A and 5B.

EXAMPLE 38 Tris-(Trimethylsilylethyl Diphenyl Phosphine) RhodiumCarbonyl Hydride as a Catalyst at Different Levels of Excess LigandConcentrations

The complex catalyst of Example 10 was tudied mainly at the 105 ppmrhodium level and at 100° reaction temperature to determine the effectof the excess trimethylsilylethyl diphenyl phosphine ligand. (SEP). TheSEP concentration used ranged from 5 to 149 mmole per liter. Somecomparative experiments were also carried out using tris-(triphenylphosphine) rhodium carbonyl hydride and varying excess concentrations ofthe corresponding triphenyl phosphine ligand. (TTP). The results ofthese studies are shown in Table V. The procedure used in the runs wasthat of Method A.

                                      TABLE V                                     __________________________________________________________________________    HYDROFORMYLATION AT DIFFERENT LEVELS OF EXCESS LIGAND CONCENTRATIONS          Feed: Butene-1 and 1:4 CO/H.sub.2 at 350 psi                                  Catalyst: L.sub.3 Rh(CO)H SEP Ligand: (CH.sub.3).sub.3 SiCH.sub.2             CH.sub.2 Pφ.sub.2 TPP Ligand: φ.sub.3 P                               Variable Conditions of Catalysts      Reaction Rates and Selectivities                             Excess Rhodium                                                                            Ligand to                                                                          Fraction of                                                                           Product                                                                             Reaction                                                                           CO                   Seq.                                                                              Catalyst                                                                            Reaction                                                                             Auto-                                                                             Ligand Conc.                                                                         Conc.                                                                              Rh Ratio                                                                           CO/H.sub.2 Reacted                                                                    Linearity                                                                           Time Conversion           No. Ligand                                                                              Temp., °C.                                                                    Clave                                                                             mMole/lit.                                                                           ppm  L/Rh k min.sup.-1                                                                          Ratio, n/i                                                                          min. %                    __________________________________________________________________________    1   SEP   100    H   5      105  5.2  0.24    3.5   20   88.7                 2                    24     105  24.2 0.09    4.0   35   87.1                 3                S   28     105  28   0.12    4.4   35   88.0                 4                    56     217  28   0.12    5.4   30   94.2                 5                    143    105  143  0.03    6.1   35   83.6                 6         120    S   29     105  29   0.30    4.5   15   93.0                 7                    60     210  30   0.25    5.7   15   89.6                 8                           149  105  0.10    6.2   35   88.1                 9   TTP   100    H   5      105  5    0.28    3.0   15   80.8                 10                   142    102  142  0.17    3.8   35   96.5                 11               S   27     105  27   0.31    4.7   15   86.6                 12                   143    104  143  0.03    6.1   35   83.6                 __________________________________________________________________________

catalyst systems. There is an apparent inhibition and stabilization ofboth systems at high ligand concentrations. However, the behavior of thetwo catalysts is significantly different at relatively low excess ligandconcentrations.

The novel SEP catalyst system leads to higher n/i product ratio than theTPP system at five mmole/l excess ligand concentration (Seq. No. 1 vs.Seq. No. 9). At the intermediate SEP concentration of 56 mmole, there isa good selectivity and sufficient reaction rate (Seq. No. 4). It isinteresting to observe that the positive effect of increasing catalystcomplex concentration on the reaction rate can be counterbalanced by theinhibiting effect of increased SEP concentration (compare Seq. Nos. 3vs. 4 and 6 vs. 7). Clearly, the SEP concentration is more importantthan the SEP/Rh ratio. At the high SEP level of 143, there is somefurther increase of the n/i ratio, but the reaction rate is cut to aboutone fourth (compare Seq. Nos. 4 and 5). At this level, the rate can beincreased while maintaining the high n/l ratio by increasing thereaction temperature (see Seq. No. 8 and the table of the previousexample).

The effect of different ligand to rhodium ratios on the n/i ratios ofbutene hydroformylation at different temperatures was further examined.The results are summarized by FIG. 6.

The figure shows that as the SEP/Rh ratio changes from about 140 toabout 1000, and n/i ratio at 80% conversion and 170° C. reactiontemperature changes from about 2 to 7. The major change in thepercentage of the n-aldehyde product occurs in the 140 to 500 L/Rhrange. It was shown in additional experiments that there was very littlefurther selectivity increase when the SEP ligand was used as the solvent(i.e., in about 75% concentration).

The increased selectivity to linear aldehyde is a consequence of theincreased catalyst stability in these experiments. The increasedcatalyst stability is also reflected in a decreasing darkening of thereaction mixture with increasing ligand concentration. Another sign ofthe increased stability is the better maintenance of thehydroformylation rate with increasing conversion. Finally, it was alsonoted that the increased ligand concentration resulted in a moderatesupression of the rate of hydrogenation. Nevertheless, hydrogenationremained significant enough to cause a decreasing H₂ /CO ratio duringthe reaction.

Similar studies of the effect of increased SEP/Rh ratio were carried outat 160°, 145° and 120° C. The data obtained at 145° are also shown inFIG. 6. The lower the reaction temperature, the less effect of increasedL/Rh ratios was observed. At decreasing temperatures most of the effectswere observed in the range of increasingly low L/Rh ratios. Also, themain effect was on selectivity rather than on stability.

EXAMPLE 39 Hydroformylation Selectivity of Tris-(TrimethylsilylethylDiphenyl Phosphine) Rhodium Carbonyl Hydride Excess Ligand CatalystSystem at Different Olefin Conversions

Butene-1 was hydroformylated in the Hastelloy unit according to thegeneral procedure by Method A. The catalyst and ligand concentrationswere higher than usual and the reaction conditions milder as shown inTable VI The reaction mixture was frequently sampled during the processand the samples were analyzed by gc to determine the relativeselectivites to n- and i-aldehyde products and hydrocarbon by-productsas a function of butene-1 conversion. The detailed data are given inTable VI.

The data of Table VI indicate that the n-to i-ratio of aldehydes in thereaction is decreasing as the conversion increases. Up to about 60%butene conversion, the n/i ratio stays above 18.5, although it issteadily dropping (see Sample Nos. 1-2). In the 72-78% conversion range,the n/i ratio is about 14. Once butene-1 conversion reaches 90%, the n/iratio of the product mixture is down to about 11.5.

It was also observed that during the conversion of about 25% of thebutene, the total aldehydes to hydrocarbon by-products ratio was lowerthan at higher conversions (about 70/30 versus 90/10). It is believedthat this is due to uncontrolled nonequilibrium conditions early duringthe reaction. Almost all the hydrogenation occurred during the first 10minutes of the reaction. During the early, very fast past of thereaction, the liquid reaction medium became starved of CO. Due to theresulting low CO partial pressure, the n/i product ratio became veryhigh. However, the amount of CO during some of this period was soinsufficient that much hydrogenation and isomerization occurred. In acontinuous process, where the low optimum concentation of CO could bemore accurately maintained, high selectivity to aldehydes could probablybe better achieved without producing significant amounts of by-products.

                                      TABLE VI                                    __________________________________________________________________________    HYDROFORMYLATION SELECTIVITY AT DIFFERENT OLEFIN CONVERSION LEVELS            Feed: Butene-1 and 1:4 CO/H.sub.2 at 130 psi at 110° C. under 130      psi                                                                           Catalyst: L.sub.3 RH(CO)H, Rh 212 ppm, L Excess 300 mMole, L/Rh 140           L: φ.sub.2 PCH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3                          Conversion Related Data Aldehyde                                                                           Mole % Selectivity to Various Compounds              Butene-1                                                                            Conversion, %                                                                          Reaction                                                                           Product                                                                            Aldehyde                                                                            Butene  2-Butene                           Sample                                                                            Conversion                                                                          Based on Time,                                                                              Linearity                                                                          Products                                                                            Hydrogenation                                                                         By-Products                        No. %     CO/H.sub.2 Consumed                                                                    Min  Ratio, n/i                                                                         n  i  Product cis                                                                              trans                           __________________________________________________________________________    1   26.4  21.9     10   26   68.4                                                                             2.7                                                                              11.9    9.7                                                                              7.3                             2   46.9  36.0     15   25   77.9                                                                             3.1                                                                              7.4     6.7                                                                              4.9                             3   61.6  50.0     20   18.5 79.7                                                                             4.3                                                                              6.1     5.8                                                                              4.2                             4   72.0  61.4     25   13.9 80.2                                                                             5.8                                                                              5.2     5.2                                                                              3.7                             5   78.0  69.4     30   14.0 79.6                                                                             5.7                                                                              5.4     5.4                                                                              3.9                             6   90.0  79.9     40   11.6 82.1                                                                             7.1                                                                              3.9     4.0                                                                              2.9                             7   90.5  87.9     60   11.3 81.9                                                                             7.2                                                                              4.0     4.0                                                                              3.0                             __________________________________________________________________________

EXAMPLE 40 Hydroformylation with the Tris-(Trimethylsilylethyl DiphenylPhosphine) Rhodium Complex System Derived Via Ligand Exchange fromTris-(Triphenyl Phosphine) Rhodium Carbonyl Hydride

In a series of experiments, tris-(triphenyl phosphine) rhodium carbonylhydride was reacted with a varying excess concentration of the novelsubstituted alkyl diphenyl alkyl phosphines. This resulted in theformation of the novel catalysts of the present invention which werestudied for their catalytic properties in the usual manner in theHastelloy unit (H).

Tris-(triphenyl phosphine) rhodium carbonyl hydride, 0.1 g (0.1 mmole),was mixed with 80 g of a mixture of 4 g (14 mmole) oftrimethylsilylethyl diphenyl phosphine and 76 g 2-propylheptyl valerateto provide an SEP catalyst system. For comparison, the same complex wasalso mixed with 80 g of a mixture of 3.7 g (14 mmole) of triphenylphosphine to provide a TPP catalyst system. This provided two systemshaving 105 ppm rhodium and a 140 fold ligand excess.

Butene hydroformylations were then carried out with both catalystsystems at 100° C. as described by Method A. The results indicated thatthe main catalytic species of the SEP system is an SEP complex. Thereaction rate of the SEP system was about 1/6 of the TPP system (k min⁻¹values of 0.02 and 0.12, respectively). The n/i product ratios wereabout the same (4.2).

Other SEP catalyst systems were made up the same way except for thedifferent L/Rh ratios: 25 and 5:1. They were also employed successfullyfor butene hydroformylation.

EXAMPLE 41 Hydroformylation with the Tris-(Trimethylsilylethyl DiphenylPhosphine) Rhodium Complex System at Different H₂ /CO Ratios

For a further study of the effect of the H₂ /CO ratios onhydroformylation selectivity, the feed gas was provided through the sidearm of the autoclave as described in Method B to provide conditionsduring the reaction which are closer to equilibrium.

The SEP complex catalyst was formed in situ during hydroformylation fromacetylacetonato dicarbonyl rhodium. The H₂ /CO ratios of both theinitial H₂ /CO gas and the final unreacted synthesis gas, in the headspace of the autoclave, were analyzed. The H₂ /CO ratio of the feed gaswas adjusted to keep the initial and final H₂ /CO ratios the same asmuch as possible.

The results are shown by Table VII. The data show that as the H₂ /COratio was increased from 1 to 20 the ratio of n- to i-aldehydes wasincreased. It is also interesting to note that having the side arm feedresulted in much less 1-butene isomerization and hydrogenation thanobtained previously with top feeding.

Comparative side arm feed experiments were also carried out using theknown TPP catalyst system at the same concentration. At 120° C.,significant side reactions continued to occur. Apparently, equilibriumconditions were not sufficiently approached. Consequently, furtherexperiments were carried out at 90° C. where the reaction rate issufficiently smaller to avoid side reactions. The results are also shownby Table VII. They show that TPP at 90° C. exhibits a similar behaviorto that of SEP at 120° C. The n/i ratios are slightly higher for TPP,apparently due to a higher average of H₂ /CO ratios.

                                      TABLE VII                                   __________________________________________________________________________    1-BUTENE HYDROFORMYLATION WITH SYNTHESIS GAS OF VARYING H.sub.2 /CO RATIO     IN THE PRESENCE OF                                                            SEP COMPLEX AND TPP COMPLEX CATALYSTS                                         Total Pressure 350 psi (260 Atm.); Catalyst: L.sub.3 Rh(CO)H; L/RH = 140,     Rh = 110 ppm                                                                  Solvent: 2-Ethylhexyl Acetate                                                                                         Aldehyde                                                 CO Partial                                                                          Fraction of    Product                               Reac-              Pressure                                                                            H.sub.2 CO Reacted                                                                           Linearity                                                                             Selectivities to Various      tion      H.sub.2 /CO Ratio                                                                      pCO, psi                                                                            Rate Conver-                                                                            Reaction %,  Compounds, %                  Seq.                                                                             Li-                                                                              Temp.                                                                             Ini-     Ini-  Constant                                                                           sion Time,                                                                              Ratio                                                                             100n                                                                              Aldehydes                     No.                                                                              gand                                                                             °C.                                                                        tial                                                                             Feed                                                                             Final                                                                            tial                                                                             Final                                                                            k, min.sup.-1                                                                      %    Min. n/i n + i                                                                             n  i  Butane                                                                            2-Butene            __________________________________________________________________________    1  SEP                                                                              120 1.18                                                                             1.08                                                                             1.36                                                                             160                                                                              149                                                                              0.115                                                                              81   13   3.09                                                                              7.56                                                                              73.7                                                                             23.8                                                                             0.6 1.8                 2  SEP                                                                              120 5.0                                                                              1.08                                                                             4.8                                                                              59 60 0.082                                                                              81   22   4.56                                                                              8.20                                                                              78.2                                                                             17.1                                                                             1.7 2.9                 3  SEP                                                                              120 10.0                                                                             1.08                                                                             7.8                                                                              31 39 0.090                                                                              82   30   6.60                                                                              86.8                                                                              80.8                                                                             12.2                                                                             2.8 3.2                 4  SEP                                                                              120 15.0                                                                             1.17                                                                             10.4                                                                             22 30 0.116                                                                              81   15   8.22                                                                              89.2                                                                              80.4                                                                             9.8                                                                              4.4 5.3                 5  TPP                                                                              90  1.08                                                                             1.08                                                                             1.8                                                                              168                                                                              125                                                                              0.060                                                                              81   29   3.76                                                                              79.0                                                                              77.0                                                                             20.5                                                                             0.8 1.7                 6  TPP                                                                              90  5.0                                                                              1.08                                                                             9.0                                                                              59 35 0.059                                                                              81   28   5.50                                                                              84.6                                                                              80.5                                                                             14.7                                                                             1.2 3.6                 7  TPP                                                                              90  10.0                                                                             1.08                                                                             10.5                                                                             31 30 0.062                                                                              80   26   6.70                                                                              87.0                                                                              81.0                                                                             12.1                                                                             2.0 4.8                 8  TPP                                                                              90  15 1.17                                                                             18 22 18 0.062                                                                              80   26   8.70                                                                              89.7                                                                              80.2                                                                             9.2                                                                              4.6 6.0                 __________________________________________________________________________

EXAMPLE 42 Hydroformylation with the Tris-(Trimethylsilylethyl DiphenylPhosphine) Rhodium Complex System at Different CO Partial Pressures

The results of the type of experiments described in Example 37 wereplotted in FIG. 7 to show the dependence of n/i aldehyde product ratioson the CO partial pressures. In additional experiments, the H₂ /COratios were kept constant with changing CO partial pressures bymaintaining an appropriate fraction of the total 350 psi (26 Atm) totalgas pressure by N₂ gas.

There was relatively little change of reaction rates.

The FIGURE shows that decreasing CO partial pressures result in highern/i product ratios even though the H₂ /CO ratio is kept constant. Thedependence of the n/i ratios is particularly strong in the low COpartial pressure range.

EXAMPLE 43 Comparative Hydroformylation withTris-(Trihydrocarbylsilylalkyl Diphenyl Phosphine) Rhodium CarbonylHyrdride Based Catalyst Systems

In a series of experiments, shown by Table VIII, various silylsubstituted alkyl diphenyl phosphine complexes of Examples 11 to 16 weretested as 1-butene hydroformylation catalysts under conditions of MethodA using top synthesis gas feed. The data indicate, that with theexception of the last catalyst, the complexes tested show the same typeof catalyst behavior as the previously discussed SEP complex. The lastcomplex tested, i.e., the one based on the tri-methylsilylmethyl ligandshowed less selectivity than the others even at the relatively lowhydroformylation temperature used in this case.

                                      TABLE VIII                                  __________________________________________________________________________    1-BUTENE HYDROFORMYLATION IN THE PRESENCE OF VARIOUS TRIS(SILYL               SUBSTITUTED                                                                   ALKYL DIPHENYL PHOSPHINE) RHODIUM CARBONYL HYDRIDE COMPLEX CATALYSTS          Catalyst: L.sub.3 Rh(CO)H, Rh = 107 ppm, Rh/L = 140                           Pressure: 350 psi (26 Atm)                                                                                      Fraction                                                                      of H.sub.2 /CO                                              Ex-               Reacted         Selec-                                                                              Selec-                                ample             Rate   Re-      tivity                                                                              tivity to                             No. Reac-         Con-                                                                              Con-                                                                             ac-      Aldehyde                                                                            By-Products,                          of  tion          stant                                                                             ver-                                                                             tion                                                                             Ra-                                                                              %, Products,                                                                           %                     Seq.                                                                             Ligand       Com-                                                                              Temp.                                                                             H.sub.2 /CO Ratios                                                                      k,  sion                                                                             Time                                                                             tio                                                                              100n                                                                             %     Bu-                                                                              2-Bu-              No.*                                                                             Structure, L plex                                                                              °C.                                                                        Initial                                                                           Feed                                                                             Final                                                                            min.sup.-1                                                                        %  Min.                                                                             n/i                                                                              n+i                                                                              n  i  tane                                                                             tene               __________________________________________________________________________    1a Ph.sub.2 PCH.sub.2 CH.sub.2 Si(C.sub.3 H.sub.7).sub.3                                      50  120 5   1.08                                                                             3.6                                                                              0.072                                                                             80 30 8.90                                                                             89.9                                                                             63.4                                                                             7.1                                                                              20.2                                                                             9.3                1b Ph.sub.2 PCH.sub.2 CH.sub.2 Si(C.sub.3 H.sub.7).sub.3                                      50  145 5   1.27                                                                             3.8                                                                              0.274                                                                             80  8 9.62                                                                             90.6                                                                             61.1                                                                             6.4                                                                              18.4                                                                             14.3               2  Ph.sub.2 PCH.sub.2 CH.sub.2 SiPh.sub.3                                                     51  145 5   1.27                                                                             7.1                                                                              0.132                                                                             80 30 7.59                                                                             88.4                                                                             73.6                                                                             9.7                                                                               8.3                                                                             8.3                3  [Ph.sub.2 PCH.sub.2 CH.sub.2 ].sub.2 Si(CH.sub.3).sub.2                                    52  145 ˜4                                                                          ˜1                                                                         -- 0.157                                                                             80 12 7.6                                                                              88.4                                                                             -- -- -- --                 4a Ph.sub.2 PCH.sub.2 CH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3                                    53  120 5   1.03                                                                             3.7                                                                              0.069                                                                             81 34 8.34                                                                             89.3                                                                             69.9                                                                             8.4                                                                              13.2                                                                             8.5                4b Ph.sub.2 PCH.sub.2 CH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3                                    53  145 4   ˜1                                                                         2.3                                                                              0.260                                                                             82  9 5.80                                                                             85.3                                                                             67.6                                                                             11.7                                                                             10.9                                                                             9.8                5  Ph.sub.2 PCH.sub.2 Si(CH.sub.3).sub.3                                                      54  100 5   1.05                                                                             5  0.056                                                                             78 60 6.24                                                                             86.2                                                                             54.3                                                                             8.1                                                                              31.8                                                                             5.9                __________________________________________________________________________     *Experiments of Seq. No. 1a and 1b were carried out in 2ethylhexyl acetat     as a solvent. The rest were in 2propylheptyl valerate.                   

EXAMPLE 44 Hydroformylation with the Tris-(Trimethylsilylethyl DiphenylPhosphine) Rhodium Complex System at High Concentrations of ExcessLigand at 145° C.

The effect of very high concentrations of excess phosphine ligands onrhodium catalyst stability and selectivity was examined in a comparativestudy of the TPP and SEP systems. The study was carried out at anapproximate H₂ /CO ratio of 5 to 1, with feed gas introduction into thestirred catalyst solution (Method C) at 145° C. At this temperature theTPP rhodium complex system is unstable at low excess phosphineconcentration.

It should be noted that at low phosphine concentrations, e.g., 0.14 M,the n/i ratio of the products is much lower when using the presentprocedure than the n/i ratios observed in previous examples. Asdiscussed earlier, lower n/i ratios result when CO starvation iseliminated.

The results of comparative experiments with TPP and SEP are shown inTable IX. The molar concentrations of both ligands in the reactionmixture range widely from about 0.14 to 3. This meant that the weightratio of the 2-ethylhexyl acetate solvent to the phosphine ligand in thestarting catalyst solution was decreased from about 20 to 0. In theextreme, the phosphine ligand was the solvent in both cases.

                                      TABLE IX                                    __________________________________________________________________________    HYDROFORMULATION OF 1-BUTENE WITH TRIS-PHOSPHINE RHODIUM CARBONYL HYDRIDE     CATALYST IN                                                                   THE PRESENCE OF INCREASING TPP AND SEP LIGAND EXCESS                          Reactions at 145°, 350 psi (24.7 Atm) of 5/1 H.sub.2 CO (54/46         H.sub.2 /CO)                                                                  Feed and 20 g 1-Butene Plus 80 g Mixture of Phosphine Plus                    2-Ethylhexyl Acetate, using Acac Rh(CO).sub.2 as catalyst Precursor and       Introducing the Feed Gas into the Stirred Reaction Mixture                                              H.sub.2 /CO Consumption                                                       Dependent Factors                                                                          Aldehyde Product                                                                                By-Product                                     (50% Conversion)     Hydroformylation                                                                        Selectivity,         Catalyst System Parameters         Reac-                                                                             Linearity                                                                             Selectivity                                                                             %                    [Ligand,L]                                                                          L Concentration                                                                           Rh          Rate tion    n×100                                                                       Total     2-                   Seq.                                                                             Run                                                                              M in Mix.                                                                           % Weight                                                                            Conc.   H.sub.2 /CO                                                                       Constant                                                                           Time                                                                              n/i n+1 n+1 n- i- Bu-                                                                              Bu-               No.                                                                              No.                                                                              at Start                                                                            in Solvent                                                                          10.sup.3 ×M                                                                 L/Rh                                                                              Final                                                                             k, min.sup.-1                                                                      min.                                                                              Ratio                                                                             %   %   %  %  tenes                                                                            tane              __________________________________________________________________________    I: φ.sub.3 P                                                              1  681                                                                              0.14  4.7   0.5  280                                                                              5.3 0.34 2.25                                                                              4.4 81.5                                                                              81.8                                                                              66.7                                                                             15.1                                                                             13.0                                                                             5.2               2  772                                                                              0.56  18.5  2    280                                                                              4.9 0.57.sup.a                                                                         1.5 7.2 87.8                                                                              80.0                                                                              70.3                                                                             9.7                                                                              14.0                                                                             5.9               3  724                                                                              0.56  18.5  0.25                                                                              2240                                                                              3.1 0.08 9.0 7.6 88.4                                                                              82.3                                                                              73.5                                                                             9.7                                                                              11.7                                                                             5.1               4  771                                                                              1.00  32.9  2    500                                                                              5.2 0.44.sup.a                                                                         2.0 11.1                                                                              91.7                                                                              82.1                                                                              75.3                                                                             6.8                                                                              12.7                                                                             5.3               5a 796                                                                              2.20  72.1  2   1100                                                                              5.2 0.18 4.0 21.5                                                                              95.0                                                                              81.0                                                                              77.4                                                                             3.6                                                                              13.5                                                                             5.5               5b 824                                                                              2.20  72.1  0.5 4400                                                                              7.2 0.07.sup.a                                                                         11  18.1                                                                              94.8                                                                              90.3                                                                              85.6                                                                             4.7                                                                               7.1                                                                             2.6               6  774                                                                              3.00  100   2   1500                                                                              3.6 0.096                                                                              9.5 31.0                                                                              96.9                                                                              73.3                                                                              71.0                                                                             2.3                                                                              19.6                                                                             7.1               II: φ.sub.2 PC.sub.2 H.sub.4 SiMe.sub.3                                   1  711                                                                              0.14  5.0   0.5  280                                                                              5.4 0.18 4.0 5.1 83.5                                                                              86.2                                                                              72.0                                                                             14.2                                                                             7.6                                                                              6.2               2b 807                                                                              0.56  20.0  2    280                                                                              6.0 0.21 3.5 9.9 90.9                                                                              86.1                                                                              78.2                                                                             7.9                                                                              8.2                                                                              5.7               3b 802                                                                              1.00  35.9  2    500                                                                              5.9 0.14 5.0 11.7                                                                              92.1                                                                              86.4                                                                              79.6                                                                             6.8                                                                              7.4                                                                              6.2               4  803                                                                              2.20  78.7  2   1100                                                                              5.6 0.07 9.5 15.1                                                                              93.8                                                                              84.0                                                                              78.8                                                                             5.2                                                                              9.1                                                                              6.9               7  805                                                                              2.80  100   2   1400                                                                              5.6 0.05 15.0                                                                              20.1                                                                              95.2                                                                              82.8                                                                              78.9                                                                             3.9                                                                              9.1                                                                              8.0               __________________________________________________________________________     .sup.a The reaction rate was decreasing with increasing conversion.      

With few exceptions, all the reaction mixtures had the same rhodiumconcentration, 2×10⁻³ M. In the case of both TPP and SEP, the reactionrate decreased with increasing ligand concentration. The rate haddecreased to about one third of the original as the ligand concentrationquadrupled from 0.56 to 2.2 M. The rate of the TPP complex catalyzedreactions was about three times greater than those of the SEP catalyzedreactions. In fact, several of the TPP runs were too fast for a reliablecontrol of the reaction conditions. In spite of this, the reaction rateswere well maintained in most of the TPP mixtures. All of the SEPmixtures showed the same rate during the reaction, up to 50% conversion.

The n/i ratio of the aldehyde products strongly depended on thephosphine excess in both cases. Although the P/Rh ratio was keptconstant when increasing the ligand concentration from 0.14 to 0.56, then/i ratio almost doubled for both TPP and SEP.

The selectivity for n-plus i-aldehydes stayed about the same in bothcases when the phosphine concentration was between 0.14 and 2.2. Thetotal aldehydes were about 82% for TPP and about 86% for SEP. However,it appeared that the total aldehyde selectivity decreased in both caseswhen the ligand was the only added solvent. The use of TPP as a solventled to a drastic decrease, i.e., to about 71% total aldehydes. When SEPwas the solvent, a minor decrease to about 83% aldehydes was observed.

The selectivity of 1-butene conversion to the 2-butenes and n-butaneby-products was, of course, inversely proportional to the selectivityfor total aldehydes. In general, the use of the TPP system resulted inmore undesired 1-butene isomerization to 2-butenes, about 12% versusabout 8%. However, the selectivity of some of the TPP systems wereadversely affected by the extremely high reaction rates which results insome CO starvation of such mixtures.

Overall, it appears that for both the TPP and the SEP based catalystsystems there is an optimum concentration. This concentration is ratherhigh. It is in the 1 to 2.2 M range. This corresponds to a 33 to 79weight % range. In other words, under these conditions, it appearspreferable to operate in catalyst solution having the phosphine as themajor component.

EXAMPLE 45 Hydroformylation with Bis-(Diphenylphosphinopropyl) DimethylSilane, i.e., BDS, Rhodium Complex System at Increasing Concentrationsof Excess Ligand and Increased CO Partial Pressure

Two series of experiments were carried out using the BDS bis-phosphineligand of Example 4 for the rhodium hydroformylation of 1-butene withMethod C. In the first series to tests (Seq. Nos. 1-5) thehydroformylations were carried out at 145° C. using starting reactionmixtures of increasing phosphorus equivalency, in the 0.14 to 2.2 Nrange (Table X, A). The second series of tests (Seq. Nos. 6-12) werecarried out in the presence of high concentrations of BDS, at increasingtemperatures and CO partial pressure (Table X, B).

The results of the first series of tests (Seq. Nos. 1-5) showed that theincreased BDS concentration resulted in increased selectivities forn-versus i-aldehyde. However, at the same rhodium concentration, theincreased BDS excess adversely affected the reaction rate. The resultsof the second series of Tests (Seq. Nos. 6-12) showed that, at the highBDS concentration, active hydroformylations can be carried out attemperatures up to 170° C. Surprisingly, increased CO partial pressuresresulted in decreased hydroformylation rates and increased activitiesfor total aldehydes under these conditions (Seq.

                                      TABLE X                                     __________________________________________________________________________    Hydroformylation of 1-Butene with Tris-Phosphine Rhodium Carbonyl Hydride     Catalyst                                                                      Using Bis-(Diphenylphosphinoethyl) Dimethyl Silane (BDS) Ligand               Reactions with 20 g 1-butene and 80 g of phosphine plus 2-ethylhexyl          acetate solvent, using AcacRh(CO.sub.2)                                       as catalyst precursor and introducing the feed gas into the stirred           reaction mixture.                                                             __________________________________________________________________________                                          H.sub.2 /CO Consumption                                                       Dependant Factors                                 Catalyst System Parameters  (50% Conversion)                        Experiment      Rh      Total                                                                              Approx                                                                             Feed                                                                              H.sub.2 /CO                                                                          Rate  Rxn                        Seq.                                                                             Run                                                                              Temp.                                                                             N.sup.a in Mix                                                                      Conc    Pressure                                                                           Pco  Ratio                                                                             Ratio  Constant                                                                            time                       No.                                                                              No.                                                                              °C.                                                                        at start                                                                            m--M                                                                              P.sup.b /Rh                                                                       (psi)                                                                              (psi)                                                                              H.sub.2 /CO                                                                       Initial                                                                           Final                                                                            Kg min.sup.-1                                                                       min.                       __________________________________________________________________________    1  202                                                                              145 0.14  0.25                                                                               560                                                                              350  60   54/46                                                                             5.1 6.4                                                                              0.052 15                         2  196                                                                              145 0.56  0.50                                                                              1120                                                                              350  60   54/46                                                                             5.1 7.2                                                                              0.038 19                         3  194                                                                              145 1.00  0.50                                                                              2000                                                                              350  60   54/46                                                                             5.0 5.5                                                                              0.025 28                         4   75                                                                              145 1.50  1.0 1500                                                                              350  60   54/46                                                                             5.5 5.7                                                                              0.040 16                         5  197                                                                              145 2.20  1.0 2200                                                                              350  60   54/46                                                                             5.1 5.5                                                                              0.025 28                         6  200                                                                              155 1.50  0.50                                                                              3000                                                                              350  60   54/46                                                                             5.0 5.5                                                                              0.030 23                         7  203                                                                              155 1.50  0.50                                                                              3000                                                                              700  120  54/46                                                                             5.0 5.7                                                                              0.035 19                         8  201                                                                              170 1.50  0.25                                                                              6000                                                                              350  60   56/44                                                                             5.0 5.1                                                                              0.021 30                         9  207                                                                              170 1.50  0.25                                                                              6000                                                                              700  120  56/44                                                                             4.9 6.5                                                                              0.033 23                         10 208                                                                              170 1.50  0.25                                                                              6000                                                                              700  280  51/49                                                                             1.5 1.7                                                                              0.044 16                         11 216                                                                              170 2.20  0.50                                                                              4400                                                                              700  120  56/44                                                                             5.0 5.8                                                                              0.047 17                         12 214                                                                              170 2.20  0.25                                                                              8800                                                                              700  280  51/49                                                                             1.5 1.5                                                                              0.014 60                         __________________________________________________________________________                              Aldehyde Product Parameters                                                   Linearity                                                                              Hydroformylation                                                                        By-product                                           Experiment                                                                              n × 100                                                                      Selectivity                                                                             Selectivity, %                                       Seq.                                                                             Run                                                                              n/i n + i                                                                              n + i                                                                             n- i- 2-                                                   No.                                                                              No.                                                                              Ratio                                                                             %    %   %  %  Butenes                                                                            Butane                      __________________________________________________________________________                        1  202                                                                              6.49                                                                              86.7 89.2                                                                              77.3                                                                             11.9                                                                              7.5 3.3                                             2  196                                                                              10.95                                                                             91.6 88.9                                                                              81.5                                                                             7.4                                                                              7.4  3.7                                             3  194                                                                              11.89                                                                             92.2 88.7                                                                              81.8                                                                             6.9                                                                              7.8  3.5                                             4   75                                                                              13.38                                                                             93.2 89.4                                                                              83.4                                                                             6.1                                                                              7.0  3.6                                             5  197                                                                              16.60                                                                             94.3 93.5                                                                              88.2                                                                             5.3                                                                              4.5  2.0                                             6  200                                                                              14.44                                                                             93.5 85.7                                                                              80.2                                                                             5.6                                                                              9.6  4.7                                             7  203                                                                              9.24                                                                              90.2 91.3                                                                              82.4                                                                             8.9                                                                              6.8  2.9                                             8  201                                                                              11.49                                                                             92.0 80.4                                                                              74.0                                                                             6.4                                                                              13.3 6.3                                             9  207                                                                              9.71                                                                              90.7 88.0                                                                              79.8                                                                             8.2                                                                              7.4  4.6                                             10 208                                                                              5.79                                                                              85.3 93.0                                                                              79.3                                                                             13.7                                                                             5.3  1.7                                             11 216                                                                              10.09                                                                             91.0 87.3                                                                              79.5                                                                             7.9                                                                              6.7  5.0                                             12 214                                                                              6.42                                                                              86.5 93.9                                                                              81.2                                                                             12.7                                                                             4.8  1.3                         __________________________________________________________________________     .sup.a Phosphorus equivalent per kg of starting reaction mixture.             .sup.b Phosphorus to rhodium ratio.   Nos. 8-10). However, as expected,       the n/i ratio of aldehydes decreased by increasing CO partial pressure.     Another, non-chelating bis-phosphine ligand bis-(diphenylphosphinopropyl)     dimethyl silane was also studied at high concentration in rhodium     hydroformylation in a similar manner. The results again showed a highly     active production of n-valeraldehyde from 1-butene.

EXAMPLE 46 Hydroformylation with the Rhodium Carbonyl Hydride Complex ofTris-(Diphenylphosphinoethyl) Methyl Silane, TDS andTetrakis-(Diphenylphosphinoethyl) Silane

The rhodium hydroformylation of 1-butene at 145° C. in the presence ofthe non-chelating tris-phosphine of Example 9 was also studied under thestandard conditions of the previous examples using Method C. The TDSligand was present at the 0.14 and 1.0 phosphorus equivalent per kgreaction mixture concentration. The H₂ /CO ratio was held at about 5 to1.

At the low TDS concentration, a n/i ratio of about 7.3 was obtained,i.e., an exceptionally high value. At the higher ligand concentration,the n/i ratio was about 10.1, a typical value for silylalkyl diarylphosphine rhodium complex systems under these conditions.

The rhodium complex of the tetrakis-(diphenylphosphinoethyl) silane waseven more unique in leading high n/i ratio of aldehyde products atrelatively low P/Rh ratios. This behavior is probably due to the stericcrowding of the starting tetra-phosphine ligand, described in Example10, and its complex derivatives.

EXAMPLE 47 Hydroformylation with Tris-Phosphine Rhodium Carbonyl HydrideSystems Having Different Ratios of the TPP and SEP Ligands at a Total of1 M Phosphine Concentration at 145° C.

The hydroformylation of 1-butene was also studied using Method C at a 1M phosphine concentration under the standard conditions of the previousexamples using TPP/SEP mixtures. The results are shown by Table XI.

In general, the data of Table XI show that the n/i ratio of the aldehydeproducts showed very little of any dependence on the TPP/SEP ratio.However, as the mole percentage of SEP in the total phosphine ligand hasincreased the amount of the total aldehyde (n+i) was also increased.

It is interesting to observe that the use of 10 mole % SEP producesquite a significant increase in the total selectivity to aldehydes (Seq.No. 2). The increased selectivity to n+i aldehydes was maintained whenthe SEP content of the phosphine ligand was increased to 20 mole %.Surprisingly, no significant decrease of the rate of hydroformylationhas occurred up to this point. The use of further increased amounts ofSEP resulted in further increased total aldehyde selectivity and also inreduced hydroformylation rate as expected.

Overall, the data indicate that TPP-SEP mixtures, containing 10 to 90,preferably 20 to 90 mole %, SEP, are unexpectedly advantageoushydroformylation catalyst systems, presumably due to the preferentialcomplexation of SEP with rhodium. The weight percentage of SEP in thesemixtures is most preferably between about 25 to 50%. Similar preferredmolar ratios and weight percentages apply to mixtures of alkyl diarylphosphines and triaryl phosphines, in general.

                                      TABLE XI                                    __________________________________________________________________________    1-BUTENE HYDROFORMYLATION WITH TRIS-PHOSPHINE RHODIUM COMPLEX SYSTEMS         HAVING VARYING RATIOS OF TPP AND DTS LIGANDS                                  Reaction at 145° C., 350 psi (24.7 Atm) of 5/1 H.sub.1 /CO             reactant, 20 g 1-Butene Feed, 1 M Total Phosphine in 2-Ethylhexyl             Acetate, 0.5 mM Rh as AcacRh(CO).sub.2 Catalyst Precursor, Introducing        54/46 H.sub.2 /CO Feed Gas into Reaction Added Mixture                        Catalyst System H.sub.2 /CO Consumption                                                                     Aldehyde Product Parameters                     Parameters      Dependent Factors      Hydroformylation                       Phosphine       (50% Conversion)                                                                            Linearity                                                                              Selectivity                                                                             By-Product                   Component   SEP     Rate Reaction n × 100                                                                      Total     Selectivity, %               Seq.                                                                             Run                                                                              Mole %                                                                              to Rh                                                                             H.sub.2 /CO                                                                       Constant                                                                           Time n/i n + i                                                                              n + i                                                                             n- i- 2-                           No.                                                                              No.                                                                              TPP                                                                              SEP                                                                              Ratio                                                                             Final                                                                             k, min.sup.-1                                                                      min. Ratio                                                                             %    %    % %  Butenes                                                                            Butane                  __________________________________________________________________________    1   9 100                                                                              -- --  6.5 0.10  7   12.3                                                                              92.5 80.8                                                                              74.7                                                                             6.1                                                                              13.6 5.6                     2  16 100                                                                              -- --  5.7 .sup. 0.05.sup.a                                                                   14   11.2                                                                              91.8 81.2                                                                              74.6                                                                             6.7                                                                              13.3 5.5                     3  10 98  2  40 6.9 0.10  7   12.5                                                                              92.6 81.1                                                                              75.1                                                                             6.0                                                                              13.2 5.6                     4  12 90 10  200                                                                              6.3 0.09  8   13.0                                                                              92.9 84.0                                                                              78.0                                                                             6.0                                                                              10.6 5.4                     5  23 80 20  400                                                                              5.9 0.07 10   12.6                                                                              97.7 83.8                                                                              77.7                                                                             6.2                                                                              10.3 5.9                     6  14 50 50 1000                                                                              6.6 0.04 16   13.3                                                                              93.0 88.2                                                                              82.0                                                                             6.2                                                                              7.3  4.6                     7  15 10 90 1800                                                                              7.0 0.03 21   12.5                                                                              92.6 88.3                                                                              81.8                                                                             6.5                                                                              7.1  4.6                     8  923                                                                              -- 100                                                                              2000                                                                              6.5 0.03 22   11.8                                                                              92.2 88.3                                                                              81.4                                                                             6.9                                                                              7.1  4.7                     __________________________________________________________________________     .sup.a [Rh] = 0.25 mM                                                    

Similar results were obtained using similar mixtures ofbis-(diphenylphosphinoethyl) dimethyl silane, BDS, and TPP. A mixture of20 phosphorus equivalent BDS and 80 phosphorus equivalent TPP led to an/i ratio of about 12 and a total aldehyde selectivity of 86.6%.

EXAMPLE 48 Hydroformylation with SEP Rhodium Complex System Using aConcurrent Addition of 1-Butene and H₂ /CO

To explore the potential effect of minimal 1-butene concentration duringthe reaction on the selectivity a hydroformylation experiment wascarried out under the conditions of the previous experiment but with aslow introduction of the 1-butene reactant. The SEP ligand was used inone molar concentration with Method C. However, 1-butene addition wasstarted only after the catalyst mixture was reached reaction condition,i.e., 145° C. and 350 psi. The 1-butene was introduced over the periodof about one hour, concurrent with the H₂ /CO feed gas. A subsequentanalysis of the reaction mixture showed substantially the sameselectivity previously obtained when starting with an appropriatesolution of 1-butene, and then subsequently feeding in the H₂ /Co feedgas.

C. Hydroformylation of Other Olefinic Compounds (Example 48A-51)

EXAMPLE 48A Hydroformylation of Propylene with the SEP Rhodium ComplexSystem

The complex of Example 10 was studied at the 458 ppm rhodium level, inthe presence of a one hundred fold excess of trimethylsilylethyldiphenyl phosphine ligand, as a propylene hydroformylation catalyst. Thereaction temperature was 100°, the 1:4 CO/H₂ pressure was 400 psi. Thegeneral procedure previously employed for butene hydroformylation wasused to carry out the reaction according to Method A.

The reaction rate was found to be k=0.04 min⁻¹, expressed as thefraction reacted. In 60 minutes, 82% conversion was reached based on theCO/H₂ consumed. The ratio of n-butyraldehyde to methylpropanal productswas 5.0. The selectivity to these aldehydes was 87.5%. The selectivityto the by-product propane was only 2.5%.

EXAMPLE 49 Hydroformylation of Miscellaneous Olefinic Compounds with theSEP Rhodium Complex System

In a series of experiments, summarized in Table XII, a number of olefinswere hydroformylated using the tris-SEP complex based catalyst system(Seq. Nos. 1-7) under conditions of Method A.

Using a high L/Rh ratio, 1-pentene was selectively hydroformylated at170° (Seq. No. 1). A lower L/Rh ratio was successfully used at 145° C.for the selective hydroformylation of 1-octene (Seq. No. 2).

A comparison of the n/i selectivities indicated that, in the absence ofisomerization, 1-n-olefins of increasing carbon number react withincreasing selectivity. Branching of terminal olefins further increasedn/i

                                      TABLE XII                                   __________________________________________________________________________    HYDROFORMYLATION OF VARIOUS OLEFINIC COMPOUNDS IN THE PRESENCE OF SEP -       RHODIUM COMPLEX BASED CATALYST SYSTEMS                                        Catalysts: L.sub.3 Rh(CO)H; L = SEP = Ph.sub.2 PCH.sub.2 CH.sub.2             Si(CH.sub.3).sub.3 ; Precursor: Dicarbonyl Acetylacetonato Rhodium;           Total Pressure 350 psi (˜26 Atm) Solvent: 2-Ethylhexyl Acetate                                        Fraction of Aldehyde                                                          H.sub.2 /CO Reacted                                                                       Product                                              Reac-             Con-                                                                             Reac-                                                                             Linearity                                                                             Selectivities to                     Rh      tion                                                                              H.sub.2 /CO Ratio                                                                      Rate ver-                                                                             tion                                                                              Ra-                                                                              %,   Various Compounds           Seq.                                                                             Olefinic                                                                            Conc.,  Temp.,                                                                            Ini-     Constant                                                                           sion                                                                             Time,                                                                             tio                                                                              100n Aldehydes                                                                           Bu-                                                                              2-Bu-              No.                                                                              Reactant                                                                            ppm L/Rh                                                                              °C.                                                                        tial                                                                             Feed                                                                             Final                                                                            k, min.sup.-1                                                                      %  Min.                                                                              n/i                                                                              n + i                                                                              n  i  tane                                                                             tenes              __________________________________________________________________________    1  1-Pentene                                                                           105 510 170 5.0                                                                               117                                                                             3.0                                                                              0.193                                                                              80 12  7.5                                                                              88.2 53.3                                                                             7.1                                                                              19.3                                                                             20.2               2  1-Octene                                                                            113  98 145 4.0                                                                              1.04  0.257                                                                              80 8   6.8                                                                              87.2                             3            141 165 4.0                                                                              1.04  0.521                                                                              80 4   5.9                                                                              85.5                             4  3-Methyl-                                                                           110 140 145 5.0                                                                              1.27                                                                             6.6                                                                              0.274                                                                              81 10  23.9                                                                             96.0 70.8                                                                             3.0                                                                              25.2                                                                             0                     butene                                                                     5* Cis-2-                                                                              447 256 170 5.0                                                                              1.27                                                                             3.6                                                                              0.018                                                                              80 150 1.0                                                                              49.5 38.7                                                                             41.4                                                                             6.1                      Butene                                                                     6**                                                                              2-Ethyl-                                                                            553  28 120 1.08                                                                             1.08                                                                             1.45                                                                             0.007                                                                              40 135 ∞                                                                          100  100                                                                              Nil                                                                              Nil                                                                              Nil                   hexene                                                                     7**                                                                              Diallyl                                                                             112 140 120 5.0                                                                              1.08                                                                             31 0.434                                                                              80 5.5 3.6                                                                              78.3                                Ether                                                                      __________________________________________________________________________     *There was a 2.6% selectivity to amyl alcohols. Both mono and                 bishydroformylated products were formed.                                      **Method B was used.                                                     

selectivity. This is shown by the example of 3-methylbutene (Seq. No.4). Internal olefins could be also hydroformylated as shown in the caseof cis-butene-2-hydroformylation (Seq. No. 5). It is important to notethat isomerization to 1-butene also occurred as indicated by theformation of n-valeraldehyde.

A terminal olefin having a substituent on a vinylic carbon, such as2-ethylhexene showed an essentially specific terminal reaction toproduce only the linear aldehyde derivative (Seq. No. 6).

Finally, an oxygenated diolefinic compound, diallyl ether, was alsosuccessfully hydroformylated without an apparent, major hydrogenationside reaction on (Seq. No. 7). Both the mono- and bis-hydroformylatedproducts could be selectively produced. At low conversions, the primaryunsaturated aldehyde products predominated. At high conversions, a highyield of the dialdehyde products was obtained. Other oxygenatedcompounds hydroformylated are allyl alcohol, allyl acetate, ethylacrylate formaldehyde.

EXAMPLE 50 Hydroformylation of an Isomer Mixture of Pentenes with theSEP Rhodium System

Two exemplary hydroformylation experiments using a mixed pentenes feedare presented in Table XIII to show that all or certain components ofolefin mixtures can be reacted. The conditions of Method A were used.

In the experiments shown by the table, the tris-SEP rhodium complex wasused in the usual manner. However, no added solvent was employed.

The data show that the 1-n-olefin component (1-pentene) was the mostreactive among the significant olefin components in both runs (Nos. 1and 2). The minor branched olefin (3-methyl butene-1) was also highly

                                      TABLE XIII                                  __________________________________________________________________________    HYDROFORMYLATION OF MIXED PENTENES WITH TRIS-                                 (TRIMETHYLSILYETHYL DIPHENYL PHOSPHINE) RHODIUM COMPLEX                       CATALYST SYSTEM                                                               Catalyst: L.sub.3 Rh(CO)H, L = SEP, L/Rh, 139; Precursor: Dicarbonyl          Acetylacetonato Rhodium; Olefin: 100 g Mixed Pentenes without Added           Solvent                                                                       __________________________________________________________________________               Reaction Conditions                                                Number     O: Feed      1  2                                                  __________________________________________________________________________    Temperature, °C. 120                                                                              120-145                                            Time, Min.              300                                                                              360                                                Olefin Conversion, %     30                                                                               55                                                Rh Conc. ppm            109                                                                              293                                                __________________________________________________________________________               Composition of Reaction Mixture                                               Mole %                                                                              Mole %                                                                              Conv. %                                                                             Mole %                                                                              Conv. %                                    __________________________________________________________________________    C.sub.2 Hydrocarbons                                                          3-Methylbutene                                                                           0.31  0     100   0     100                                        i-Pentane  0.45  0.53  --    1.02  --                                         1-Pentene  8.04  0.89  89    0.71  91                                         2-Methylbutene                                                                           24.61 19.13 22    7.14  71                                         n-Pentane  4.14  5.10  --    6.10  --                                         t-2-Pentene                                                                              28.97 19.95 31    5.63  81                                         c-2-Pentene                                                                              12.32 7.35  40    2.19  82                                         2-Methylbutene-2                                                                         21.04 22.22  0    22.46  0                                         Aldehydes  None                                                               2-Methylpentanal                                                                         --    13.86       27.33                                            3-methylpentanal                                                                         --    5.69        16.97                                            4-methylpentanal                                                                         --    --          --                                               n-hexanal  --    5.27        10.46                                            __________________________________________________________________________

reactive. High conversions of the internal olefin components (cis- andtrans-pentene-2's) and the olefinically substituted terminal olefin(2-methylbutene) could be also realized under the more forcingconditions of Run No. 2. It is noted that under the latter conditionssome darkening of the reaction mixture occurred indicating some longterm instability.

EXAMPLE 51 Hydroformylation 2-Butene with the SEP Cobalt Complex System##STR22##

2-Butene was hydroformylated with a SEP complex of cobalt, presumablySEP tricarbonyl cobalt hydride, because cobalt compounds often catalyzeolefin isomerization as well as hydroformylation. In the case of2-butene, combined isomerization-hydrofomylation is desired to obtainn-valeraldehyde via 1-butene.

As a precursor of the cobalt complex, dicobalt octacarbonyl was used indecane solution to provide a cobalt concentration of 0.2%. The SEP/Coratio was 4. The main solvent was 2-ethylhexylacetate. About 20 g of the2-butene reactant was used in the 100 g reaction mixture. The olefin wasadded at 175° C. The reaction was run at that temperature having 1/l H₂/CO initial gas followed by 52/48 run gas introduced at the bottom(Method C) of the mixture at a total pressure of 1000 psi (about 68 Atm)total pressure to a CO/H₂ consumption based conversion of 50% in 47minutes.

An analysis of the reaction mixture by glc showed the formation of 38mole % valeraldehydes of a n/i ratio of 5.2. About 15% of the twoisomeric amyl alcohols of a n/i ratio of 13.4 were also formed. Themixture also contained 3.1 mole % 1-butene isomerization product and 3.3mole % butane hydrogenation product.

D. Continuous Hydroformylation

EXAMPLE 52 Continuous Hydroformylation with the SEP and TPP Systems

The tris-(trimethylsilylethyl diphenyl phosphine) rhodium carbonylhydride catalyst system was extensively studied in a continuoushydroformylation unit. The feed was butene-1 and the products werecontinuously removed together with the unreacted volatile components ofthe reaction mixture. The typical reaction temperature for the SEP basedsystem was 120° C. Comparative runs were also carried out with a similarTPP based system at 100° C. Both systems could be successfully operatedon the short run although it appeared that the known degradationreactions and the stripping of the valeraldehyde trimer by-product at100° C. could become a problem with TPP. The SEP system showed anexcellent long term stability and activity maintenance.

A representative 30 day continuous operation of the operation of the SEPcatalyst system is illustrated by FIG. 8. With regard to the continuousoperating conditions, it is noted that the total synthesis gas pressurewas lower (125 psi, 8.5 Atm) and the H₂ /CO ratio higher (10/1) than inmost of the batch studies. Also a higher concentration of rhodium (270ppm) and a higher L/Rh ratio (210) were employed. Under these conditionsa batch experiment produced results similar to those found in thecontinuous operation.

In the continuous hydroformylation the catalyst was generated fromdicarbonyl acetylacetonato rhodium in situ. In a typical operation1-butene was introduced into the reactor at a rate of 4.4 mole per hour.The rate of CO was typically 2 standard cubic feet per hour (SCFH). Thehydrogen was introduced in the 15 to 25 SCFH range. By changing thehydrogen/CO ratio the aldehyde production rate and other parameterscould be appropriately and reversibly controlled.

During the reaction isomeric valeraldehyde trimers and some tetramerswere formed. At an equilibrium concentration they were in theconcentration range from about 50 to 80% by wt.

After the reaction system came to an equilibrium, the rate of hydrogengas feed introduction was decreased from 19.2 to 17.6 SCFH (standardcubic feet per hour; 1 SCFH=28.3 dm³ /hr) during the seventh day of therun. This resulted in an increased production rate. As expected, thisprocess was fully reversible. Also, a increase of the synthesis gas feedrate above the initial level of 24.5 SCFH on the 15th day resulted inthe expected decreased production rate.

On the nineteenth day, the reaction temperature was raised to 125° C.This resulted in an about 39% reaction rate increase as expected on thebasis of an activation energy of 15.4 kcal. Subsequent changes of thespace velocity of the synthesis gas feed at this higher temperatureresulted in the expected reaction rate changes.

On the basis of the kinetic changes observed during the approximately 3weeks of operation shown by the figure and on the basis of othercontinuous hydroformylations with the same catalyst system, a rateequation was developed. The rate equation did fit all the data. The rateconstant remained unchanged after the startup equilibrium period for the25 days shown. It is noted that the lack of change of the rate constantmeans that there is no loss of catalyst activity during this period. Theonly long term change in the catalyst system was some oxidation,probably by oxygen, of the phosphine ligand to the correspondingphosphine oxide. In the presence of excess phosphine, this oxidation hadno adverse effect on the reaction rate. Combined gas chromatography andmass spectroscopy studies could not show any evidence of a liganddegradation similar to that reported to occur via o-phenylation in theTPP system.

EXAMPLE 53 Comparative Performance of Rhodium Complex Catalyst Systemsbased on SEP and TPP in Continuous Hydroformylation

Operating with the SEP rhodium system at 120° C. hydroformylationselectivities could be obtained which were similar to those obtained at100° C. with the TPP rhodium system. However, higher conversion could berealized with SEP. The comparative operational parameters and theselectivities to products and by-products obtained are shown in TableXIV.

The data of the table show that the most important parameters for high1-butene conversion per pass are the reaction temperature and thestripping gas rate. These parametes control the rate of productflashoff. At the stripping gas rate of 38 g mole per hour per liter, a38-50% 1-butene conversion was obtained when the thermally more stableSEP system was used at 120° C. The same stripping rate resulted in only25-27% 1-butene conversion at 100° C. with the TPP system. This showsthat the higher stability of the SEP system can be used to advantage ina high conversion process. The n/i ratio of the aldehydes and theselectivity to by-products are about the same for both catalyst systems.

                  TABLE XIV                                                       ______________________________________                                        COMPARATIVE PERFORMANCE OF RHODIUM                                            COMPLEX SYSTEMS BASED ON SEP AND TPP IN                                       CONTINUOUS 1-BUTENE HYDROFORMYLATION IN A                                     PRODUCT FLASHOFF MODE                                                                        Rhodium Complex of                                                            SEP     SEP     TPP                                            ______________________________________                                        Operating Parameters                                                          Temperature, °C.                                                                        120       120     100                                        Pressure, psia   150       150     115                                        1-Butene feedrate, M/hr                                                                        4.0       4.0     4.0                                        H.sub.2 /CO ratio in feed                                                                      7.5       8.0     7.5                                        Rhodium, ppm     260       480     260                                        P/Rh ratio       250       135     140                                        Stripping gas rate,                                                                             26        38      38                                        g mole/hr/liter                                                               Conversion and Products                                                       1-Butene conversion, %                                                                         25-27     38-40   25-27                                      Valeraldehyde production                                                                       1.0-1.1   1.4-1.5 1.0-1.1                                    rate, m/hr/1                                                                  n/i Aldehyde ratio                                                                             20-25     20-23   20-23                                      Selectivity to By-Products                                                    Butane           2-3       2-5     1-2                                        2-Butenes        2-5       2-5     3-5                                        Aldehyde dimers  0.2       0.2     0.1                                        Aldehyde trimers 0.2-0.4   0.2-0.4 0.3                                        ______________________________________                                    

EXAMPLE 54 Continuous Hydroformylations Using 1-Butene and Mixed ButenesFeed at 145° C.

The SEP rhodium catalyst system was also employed for the continuoushydroformylation of 1-butene at 145° C. For maintaining catalystselectivity and stability at this temperature, the ligand concentrationwas increased to 1 mole/liter. The rhodium concentration was alsoincreased to 4.17 mmoles/liter to assure high olefin conversion per passin a continuous product flash-off operation. The hydroformylationprocess was carried out under identical pressure, temperature and H₂ /COfeed rate conditions, using a pure 1-butene feed at first for a periodof six days, and then a mixture of 1- and 2-butenes for a subsequentsix-day period. Details of the reaction conditions and results are shownby Table XV.

The pure and the mixed feeds were introduced at a different rate intothe reactor to provide the 1-butene reactant at the same rate. In thecase of the pure reactant, the performance was compared with that of theTPP-rhodium system.

A comparison of the data of Table XV shows that 1-butene was selectivelyhydroformylated to n-valeraldehyde regardless of the feed used. Theselectivities were nearly identical. The stability of the SEP complexsystems was excellent in both cases during the six day reaction period.The only change was due to the loss of some of the ligand by flash-off.

The comparative experiment with the TPP-rhodium system and 1-butenereactant showed ligand degradation. About 1/2% per day of butyl diphenylphosphine was derived from the TPP in this system. This resulted in asignificant activity loss during the reaction. Also, more C₄by-products, particularly 2-butenes, were obtained.

                                      TABLE XV                                    __________________________________________________________________________    Continuous Hydroformylation of Mized n-Butenes                                and Pure 1-Butene Feed in a Product Flashoff Mode                             at 140° C. During a Six-Day Period                                     All the reaction mixtures contain 1 P-equivalent/1 ligand,                    4.17 mM/1 (460 ppm) rhodium complex (P/Rh = 240). The                         total pressure is 185 psi. The rate of feed introduction                      in mL is the following: H.sub.2, 23.4; CO, 4.8 (H.sub.2 /CO 4.9)                               Rhodium Complex of                                                            SEP   SEP   TPP  BDS.sup.(b)                                 __________________________________________________________________________    1-Butene Reactant Employed                                                                     Mixture.sup.(a)                                                                     Pure  Pure Pure                                        Reactant feed rate, 1-butene, m/hr                                                             2.75  2.75  2.75 2.75                                        total feed, m/hr 4.60  2.75  2.75 2.75                                        Conversion and Selectivity                                                    1-Butene conversion, %                                                                         56.1-51.8                                                                           57.4-54.8                                                                           82.1-65.5                                                                          57.0                                        Total aldehydes, %                                                                             82.8  85.2  77.9 85.5                                        n/i aldehyde ratio                                                                             13.1  12.3  11.7 14.4                                        Selectivity to By-Products, %                                                 Butane           4.4   3.8   5.9  4.1                                         2-Butenes        9.1   7.6   12.9 7.1                                         Aldehyde dimers  0.7   0.5   0.1  0.6                                         Aldehyde trimers 0.4   0.6   0.4  0.6                                         Alcohols         2.6   2.3   2.8  2.0                                         __________________________________________________________________________     .sup.(a) The percentage composition of the reactant mixture is 1butene,       59.6; 2butenes, 31.0; n and ibutanes, 6.8; ibutene, 1.4 and butadiene,        0.02; others, 1.1.                                                            .sup.(b) Bis(2-diphenylphosphinoethyl) dimethyl silane of Example 4.     

A non-volatile silyl substituted bis-phosphine,bis-(2-diphenylphosphinoethyl) dimethyl silane, BDS based rhodiumcomplex catalyst was also tested for 1-butene hydroformylation under thesame conditions. As is shown by Table XV, the use of this ligand led toslightly improved but generally similar catalyst selectivities. However,the activity of the catalyst and the composition of the catalyst complexdid not change whatsoever under the reaction conditions.

Combined Hydroformylation-Aldolization (Examples 55-58)

EXAMPLE 55 Combined Hydroformylation-Aldolization of 1-Butene at 120° C.in the Presence of Tris-(Trimethylsilylethyl Diphenyl Phosphine [SEP]Rhodium Carbonyl Hydride Complex ##STR23##

The combined hydroformylation, aldolization and hydrogenation ofbutene-1 was studied under typical conditions of the presenthydroformylation process. The SEP rhodium complex was utilized as atypical substituted alkyl diaryl phosphine rhodium complex catalyst forhydroformylation and hydrogenation. Potassium hydroxide inmethoxytriglycol was employed as an aldolization catalyst. Themethoxytriglycol was also used as the solvent for the other componentsof the mixture. The catalyst system was employed at the 110 ppm rhodiumconcentration level. The ligand to rhodium ratio was 140. The 1-butenereactant was employed in a standard manner. The initial H₂ /CO mixtureused to pressure the mixture to 350 psi (25 atm) had a 5/1 mole ratio.The feed gas to maintain this pressure was a 1.5 to 1 mixture. Thelatter ratio was employed because it is theoretically needed to producethe n,n- and i,n-anals. The feed gas was introduced at the top of thereactor according to Method A.

The reaction and product parameters of a group of experiments designedto observe the effect of varying concentrations of KOH are summarized inTable XVI. The

                                      TABLE XVI                                   __________________________________________________________________________    Combined Hydroformylation-Aldolization of 1-Butene at 120° C. and      350 psi (˜2 atm.)                                                       in the Presence of SEP Rhodium Complex and Varying Amounts of KOH             SEP = L = Ph.sub.2 PCH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3 ; L/Rh = 140; Rh     = 110 ppm                                                                                            Fraction of    Approx. Selectivities                                          H.sub.2 /CO Reacted                                                                          to Aldehydes                            Run                    Rate Con-                                                                              Reaction                                                                            Mole %          %                                                                                Selectivity          Seq.                                                                             No. KOH, H.sub.2 /CO Ratio                                                                        Constant                                                                           version                                                                           Time  C.sub.5's                                                                          n,n(i)-                                                                           n,n-                                                                             n/i 100n                                                                             to n-Butane          No.                                                                              7132                                                                              %    Initial                                                                           Feed                                                                             Final                                                                             k, min.sup.-1                                                                      %   Min.  i n  anal                                                                              enal                                                                             Ratio                                                                             n+1                                                                              mole                 __________________________________________________________________________                                                             %                    1  280 Nil  5   1.08                                                                             2.7 0.056                                                                              80  50    9.2                                                                             90.8      9.9    14.0                 2  306 Nil  5   1.5                                                                              24.1                                                                              0.051                                                                              80  42    3.0                                                                             97.0      32.1                                                                              97.0                                                                             18.8                 3  307 Nil  5   1.5                                                                              26.8                                                                              0.05 15  4     3.3                                                                             96.7      29.1                                                                              96.7                                                80  48    3.1                                                                             96.9      31.5                                                                              96.9                                                                             15.1                 4  286 Nil  5   1.50                                                                             21.3                                                                              0.042                                                                              15  6     6.7                                                                             93.3      13.8                                                    45  15    5.8                                                                             94.2      16.3                                                    60  24    5.5                                                                             34.5      17.2                                                    80  80    6.2                                                                             93.8      15.0                                                                              93.8                                                                             17.7                 5  283 0.05 5   1.50                                                                             47  0.059                                                                              80  34    4.1                                                                             47.5                                                                             8.4 40.0                                                                             34.9                                                                              97.2                                                                             28.9                 6  285 0.05 5   1.50                                                                             17.7                                                                              0.061                                                                              15  4     6.1                                                                             81.6                                                                             0.8 11.7                                                                             17.6                                                                              94.6                                                30  18    5.5                                                                             76.8                                                                             1.0 16.7                                                                             20.5                                                                              95.4                                                45  11    5.4                                                                             72.9                                                                             1.5 20.2                                                                             21.6                                                                              95.6                                                60  16    5.2                                                                             67.3                                                                             2.7 24.7                                                                             23.5                                                                              95.9                                                80  30    5.9                                                                             51.5                                                                             7.8 34.8                                                                             23.2                                                                              95.9                                                                             17.7                 7  301 0.10 5   1.17                                                                             6.52                                                                              0.062                                                                              15  5     2.9                                                                             17.8                                                                             3.0 50.2                                                                             42.9                                                                              94.3                                                80  32    9.3                                                                             34.1                                                                             13.0                                                                              43.6                                                                             15.8                                                                              77.1                                                                             15.0                 8  281 0.10 5   1.50                                                                             5.0 0.048                                                                              80  42    3.4                                                                             27.1                                                                             18.3                                                                              51.2                                                                             49.2                                                                              98.0                                                                             31.3                 9  279 0.20 5   1.50                                                                             5.0 0.043                                                                              80  40    2.9                                                                             16.0                                                                             16.0                                                                              65.2                                                                             60.5                                                                              98.4                                                                             28.8                 10 288 0.20 5   1.50                                                                             13.6                                                                              0.049                                                                              15  3     --                                                                              -- 10.8                                                                              89.2                                                                             ∞                                                                           --                                             0.028                                                                              30  5     3.7                                                                             -- 11.5                                                                              84.9                                                                             50.6                                                                              98.0                                                45  12    3.0                                                                             -- 12.0                                                                              85.0                                                                             64.4                                                                              98.5                                                60  16    3.3                                                                             7.5                                                                              13.6                                                                              75.8                                                                             57.1                                                                              98.3                                                80  32    3.6                                                                             17.7                                                                             18.6                                                                              60.1                                                                             48.0                                                                              98.0                                                92  62    4.9                                                                             14.1                                                                             34.5                                                                              46.5                                                                             35.9                                                                              97.3                                                                             16.0                 __________________________________________________________________________

product parameters, i.e., selectivities to the various products wereobtained by glc analyses. For the analyses of the C₅ and C₁₀ aldehydes,a special 2m Carbowax column 10% CW on Chromosorb P diatomaceous earthwas used. This was provided by Supelco, Inc., Supelco Park, PA. Itprovided good separation of the n,n-enal was not good. The smallquantities of the i,n-enal formed could not be determined. Therefore,the overall n,i-ratios in the reaction mixtures with KOH could not beexactly determined. The aldehyde selectivity to the main final C₁₀aldehyde products, the n,n-enal, also includes minor quantities of thei,n-anal. However, this inclusion causes less than 10% change in thecomposition, since the minor i-C₅ aldehyde is cross-aldolized at a veryslow rate. The glc percentages are indicated on the basis of the peakintensities. No corrections were made for the possibly different glcresponse to C₅ and C₁₀ compounds.

In the first four experiments, the hydroformylation of butene wasstudied in methoxytriglycol but in the absence of KOH aldolizationcatalyst (Seq. Nos. 1 to 4), for comparison. All three experimentsstarted with 5/1 H₂ /CO gas. In the first experiment, the H₂ /CO ratioof the feed gas was close to one as usual. This experiment gave theusual high n/i ratio of C₅ aldehydes. This indicated that the solvent isan acceptable one.

The rest of the experiments used the same initial H₂ /CO ratio of 5 buta different H₂ /CO feed of 1.5. Also, the contents of the third andfourth reaction mixture were sampled for comparison with the experimentsusing added KOH. This and other sampled runs provided less reliableabsolute values than the uninterrupted experiments. However, they gavecomparative relative numbers which showed the change of selectivity withthe increasing conversion.

The second experiment (Seq. No. 2) showed a much increased n/i ratiocompared to the first. This was the consequence of the increasing H₂ /COratio, i.e., decreasing CO partial pressure due in the reaction. Due todecreased availability of CO, this run also resulted in morehydrogenation of the 1-butene starting material and isomerized 2-butenesto n-butane.

The results of the first sampled experiment are somewhat similar. Thisexperiment shows that as a consequence of increasing H₂ /CO ratio, theselectivity is much higher at 80% conversion (Seq. No. 3).

The fourth experiment (Seq. No. 4) was sampled four times during therun. It showed that up to 60% conversion, the n/i ratio was moderatelyincreasing as an apparent consequence of the increasing H₂ /CO ratio inthe reaction mixture.

The second group of experiments (Seq. Nos. 5-10) was run using varyingamounts of KOH, in the 0.05 to 0.2% range, under the same conditions.The data indicated that 0.2% KOH was sufficient for the rapid conversionof the primary n-C₅ aldehyde product eq. Nos. 7 and 8). The aldolizationrate was much slower when 0.05% KOH was used (Seq. Nos. 5 and 6). Therate of the hydroformylation was estimated on the basis of the measuredrate of synthesis gas consumption.

Increasing H₂ /CO ratios generally resulted in increased n/i ratios andincreased percentages of n-butane formation. Due to apparent COstarvation, the non-sampled mixtures gave rise to significantly higherH₂ /CO ratios than those frequently sampled during the run.

The hydrogenation of the unsaturated aldehyde to the saturated aldehydewas relatively low. At 45% synthesis gas conversion, the percentagen,n-anal formed was less than 10% of the n,n-enal present. At thatconversion, the overall selectivity to the n,n-enal was in excess of80%.

EXAMPLE 56 Sequential Hydroformylation, Aldolization, Hydrogenation inSeparate Steps

In a series of experiments, n-valeraldehyde was produced by thehydroformylation of B 1-butene and separated from the i-isomer. A 20%methoxytriglycol solution of the n-valeraldehyde was then aldolized toprovide the n,n-enal condensation product. It was observed that thealdolization was much slower in the absence of the hydroformylationcatalyst system in the presence of it in the previous example. After 30minutes reaction time, only a 1.2% conversion was reached. After 14hours, the aldehyde conversion was 47.2%, i.e., the concentration of then,n-enal in mole equivalents was 47.2%.

During the above experiment, and other experiments with KOH solutions inmethoxytriglycol, yellow, then amber, then brown color formation wasobserved indicating potential instability. The addition of 2% KOH tomethoxytriglycol resulted in an amber color even at room temperature.Therefore, the amount of KOH in the hydroformylation experiments wasminimized.

To the reaction mixture from the above aldolization experiment, thehydroformylation catalyst of the previous example was added. Then themixture as pressured to 570 psi (39 atm) and heated as usual to 120° C.with a 20/1 mixture of H₂ /CO. A high H₂ /CO ratio was used to increasethe hydrogenation rate of the n,n-enal to the n,n-anal.

The hydrogenation of the n,n-enal to the n,n-anal was followed by glc.During the first 90 minutes, the percentage conversion increased asfollows: 6% (5 min.); 13% (20 min.); 21% (40 min.); 28% (60 min.); and39% (90 min.). Under these conditions, no further significantaldolization of the n-C₅ aldehyde occurred.

EXAMPLE 57 Combined Hydroformylation-Aldolization of 1-Butene withVarious Tris-(Alkyl Diphenyl Phosphine) Rhodium Carbonyl HydrideComplexes

The combined hydroformylation aldolization of 1-butene under theconditions of Example 56 was also studied with the tris-(n-butyldiphenyl phosphine) and the tris-(n-hexyl diphenyl phosphine) complexes.The SEP complex was also used in this group of experiments under similarconditions but using a 1/1 rather than a 5/1 initial H₂ /CO reactantratio. The results are shown in Table XVII.

Overall, the data of the Table show that different alkyl diphenylphosphine complexes are similar catalysts for combined hydroformylationaldolization. The results also indicate that the provision of sufficientcarbon monoxide for hydroformylation is a key factor in avoiding olefinhydrogenation.

The first two experiments seq. Nos. 1 and 2) with the butyl diphenylphosphine complex A) show the effect of the KOH on the aldolization. Theresults are similar to those obtained in comparative experiments usingthe SEP complex in a previous example (see Table I). The second pair(Seq. Nos. 3 and 4) shows the effect of starting with a synthesis gashaving a low, i.e., B 1.5, H₂ /CO ratio. Lower selectivities to then-product are obtained but the reaction rates are increased and theby-product are obtained but the reaction rates are increased and theby-product n-butane formation is drastically reduced. The two differentcatalyst ligands used in these experiments, i.e., n-hexyl diphenylphosphine (B) and trimethylsilylethyl phosphine (C), led to similarresults.

EXAMPLE 58 Combined Hydroformylation Aldolization of 1-Butene at 145° C.in the Presence of Tris-SEP and Tris-TPP Rhodium Carbonyl HydrideComplexes

The combined hydroformylation-aldolization of

                                      TABLE XVII                                  __________________________________________________________________________    Combined Hydroformylation Aldolization of 1-Butene at 120° C., in      the Presence of Various                                                       tris-(Alkyl Diphenyl Phosphine) Rhodium Carbonyl Hydride Complexes            L = Ar.sub.2 PR; A: R = C.sub.4 H.sub.9 ; B: R = C.sub.6 H.sub.13 ; C: R      = CH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3 ; L/Rh = 140; Rh = 110 ppm;            Pressure = 350 psi (26 atm)                                                                                        Approximate Selectivities                                        Fraction     to Aldehydes         Selec-                                      H.sub.2 /CO Reacted                                                                    Reac-                                                                             Mole %               tivity              Run                     Rate Con-                                                                              tion      C.sub.10 's                                                                              % n to n-               Seq.                                                                             No.                                                                              Ligand                                                                            KOH H.sub.2 /CO Ratio                                                                       Constant                                                                           version                                                                           Time                                                                              C.sub.5 's                                                                          n,n(i)                                                                            n,n-                                                                             n/i 100n                                                                              Butane              No 7132                                                                             Species                                                                           %   Initial                                                                           Feed                                                                             Final                                                                            k, min.sup.-1                                                                      %   Min.                                                                              i- n  anal                                                                              enal                                                                             Ratio                                                                             n                                                                                 mole                __________________________________________________________________________                                                              %                   1  303                                                                              A   Nil 5   1.5                                                                              20.1                                                                             0.058                                                                              15  4   4.9                                                                              95.1      19.6                                                                              95.1                                                 80  34  4.4                                                                              95.6      21.9                                                                              95.6                                                                              13.0                2  290                                                                              A   0.1 5   1.5                                                                              21.0                                                                             0.043                                                                              15  5   10.7                                                                             16.8                                                                             7.3 65.2                                                                             15.1                                                                              93.8                                                 80  42  6.7                                                                              24.5                                                                             21.9                                                                              46.9                                                                             24.1                                                                              96.0                                                                              13.7                3  299                                                                              B   0.1 1.5 1.5                                                                              11.6                                                                             0.151                                                                              15  2   18.5                                                                             75.2   7.3                                                                              4.8 82.8                                                 80  12  14.1                                                                             63.1                                                                             6.7 16.0                                                                             7.7 88.5                                                                              1.9                 4  293                                                                              C   0.1 1.5 1.5                                                                              6.8                                                                              0.088                                                                              15  3   18.0                                                                             75.7   6.3                                                                              4.9 83.1                                                 80  20  16.0                                                                             73.6                                                                             0.9 9.5                                                                              5.9 88.5                                                 109 120 19.0                                                                             12.8                                                                             34.4                                                                              33.8                                                                             7.5 88.2                                                                              2.1                 __________________________________________________________________________

1-butene was also studied under similar conditions at 145° C. At thistemperature, the known tris-TPP complex is unstable under the reactionconditions. In contrast, the novel tris-SEP complex is stable under thereaction conditions. In contrast, the novel tris-SEP complex is stable.The experimental conditions and results are shown in Table XVIII.

As it is shown by the table, in the first pair of experiments (Seq. Nos1 and 2), both the triphenyl phosphine (TPP) complex and thetrimethylsilylethyl diphenyl phosphine (SEP) complex were employed ashydroformylation catalysts in methoxytriglycol in the absence of KOH. Acomparison of the results showed that the rate of the SEP complexcatalyzed reaction was higher. Even more significantly, the selectivity'of the SEP complex to produce aldehydes of high n/i ratios was muchhigher (Seq. No. 1). At 80% conversion, the SEP catalyzed reaction had a7.6 n/i ratio. The comparable ratio for the TPP system was 3.1 (Seq. No.2). Most revealingly, the TPP reaction gave an n/i ration of 12.4 at 15%conversion. Apparently, during the further course of the experiment, theTPP catalyst system decomposed and led to species of much lowercatalytic activity and selectivity.

In the second pair of experiments (Seq. Nos. 3 and 4), the same twocatalyst systems were employed in the presence of KOH to effecthydroformylation and aldolization. KOH was found to be an effective aaldolization catalyst. Both complexes were also effective in catalyzingthe hydrogenation of the aldol condensation products. However, thedifference between the activity and selectivity of the two catalystsremained. The SEP complex plus KOH system produced a 6.6 n/i ratio ofaldehydes at 80% conversion (Seq. No. 3). The comparative n/i ratio forthe TPP complex plus base was only 4.2 (Seq. No. 4).

                                      TABLE XVIII                                 __________________________________________________________________________    Combined Hydroformylation Aldolization of 1-Butene at 145° C. and      350 psi (˜26 atm.) in the                                               Presence of tris-SEP and tris-TPP Rhodium Carbonyl Hydride Complexes          SEP = Ph.sub.2 PCH.sub.2 CH.sub.2 Si(CH.sub.3).sub.3 ; TPP = Ph.sub.3 P;      L/Rh = 140; Rh = 110 ppm                                                                                           Approximate Selectivities                                        Fraction     to Aldehydes         Select-                                     H.sub.2 /CO Reacted                                                                    Re- Mole %               ivity               Run                     Rate Con-                                                                              action    C10's      % n to n-               Seq.                                                                             No.                                                                              Ligand                                                                            KOH H.sub.2 /CO Ratio                                                                       Constant                                                                           version                                                                           Time                                                                              C5's  n,n(i)                                                                            n,n-                                                                             n/i 100n                                                                              Butane              No 7132                                                                             Species                                                                           %   Initial                                                                           Feed                                                                             Final                                                                            k, min.sup.-1                                                                      %   Min.                                                                              i- n  anal                                                                              enal                                                                             Ratio                                                                             n                                                                                 mole                __________________________________________________________________________                                                              %                   1  238                                                                              SEP Nil 5    1.17                                                                            2.7                                                                              0.174                                                                              79  18  11.6                                                                             88.4      7.6 88.6                                                                              12.0                2     TPP Nil 5   1.5                                                                              14.7                                                                             0.138                                                                              15  1   7.5                                                                              92.5      12.4                                                                              92.5                                                 80  90  24.6                                                                             75.4      3.1 75.4                                                                              15.4                3  262                                                                              SEP 0.2 5   1.5                                                                              4.6                                                                              0.07 80  42  15.2                                                                             21.1                                                                             44.4                                                                              19.4                                                                             6.7 87.0                                                                              19.4                4  295                                                                              TPP 0.1 5   1.5                                                                              6.4                                                                              0.121                                                                              15  1.5 8.6                                                                              38.4                                                                             3.0 50.0                                                                             16.8                                                                              94.4                    4  295                                                                              TPP 0.1 5   1.5                                                                              6.4                                                                              0.121                                                                              15  1.5 8.6                                                                              38.4                                                                             3.0 50.0                                                                             16.8                                                                              94.4                                                 80  80  29.7                                                                             12.0                                                                             48.5                                                                              9.8                                                                              4.2 80.6                                                                              13.2                __________________________________________________________________________

The above quantitative observations on the relative stability of the SEPand TPP based systems could be qualitatively predicted when observingthe respective reaction mixtures after the reactions. The SEP systemswithout and with base were yellow and amber, respectively. The TPPsystems with and without base became black.

What is claimed is:
 1. A combined hydroformylation-aldolization process for converting, a C_(n) olefin to a C_(2n+2) aldehyde comprising the steps of:(a) reacting said olefin with CO and H₂ at a temperature in the range of about 50° to 200° C. and a total pressure in the range of about 15 to 2000 psia in a reaction zone containing a liquid reaction mixture comprising a base aldol condensation catalyst and a homogeneous, non-charged catalyst complex of the formula:

    [(Ar.sub.2 PQ).sub.y SiR.sub.4-y ].sub.g.(RhX.sub.n).sub.s

wherein Ar is a substituted or unsubstituted C₆ to C₁₀ aromatic radical, Q is an unsubstituted or substituted C₁ to C₃₀ saturated open chain alkylene radical; R is an unsubstituted or monosubstituted C₁ to C₁₀ hydrocarbyl radical, X is an anion or organic ligand, excluding halogen, satisfying the valence and coordination sites of the metal, y is 1 to 6, g is 1 to 6 with the proviso that g times y is 1 to 6, n is 2 to 6, s is 1 to 3, said substituents on said hydrocarbyl radical, being chemically unreactive with materials used in and the products of the hydroformylation reaction, and (b) withdrawing said liquid reaction mixture from said reaction zone and recovering said C_(2n+2) aldehyde.
 2. The process of claim 1 wherein said hydroformylation products further comprise hydrogenation products of said C_(2n+2) aldehydes.
 3. The process of claim 1 wherein the H₂ /CO ratio is greater than three, the ligand/Rh molar ratio is greater than 140 and wherein the process temperature is between 120° to 175° C.
 4. The process of claim 1 wherein the catalyst complex is tris(2-trimethylsilylethyl diphenyl phosphine) rhodium carbonyl hydride.
 5. The process of claim 1 wherein said liquid reaction mixture is a homogeneous phase.
 6. The process of claim 1 wherein said aldol condensation catalyst is KOH present in about 0.05 to 0.5 weight percent of the total liquid reaction mixture.
 7. The process of claim 1 wherein said liquid reaction mixture contains an ether-alcohol solvent.
 8. The process of claim 1 wherein said catalyst is of the formula:

    {[Ph.sub.2 P(CH.sub.2).sub.m ].sub.y Si(CH.sub.3).sub.4-y }.sub.g Rh(CO)H

wherein m is 2-14, Ph is phenyl, and y and g are as described above in claim
 9. 9. The process of claim 1 wherein said olefin is a terminal olefin.
 10. The process of claim 1 wherein said olefin is a mixture of butene-1 and cis- and trans-butene-2.
 11. The process of claim 1 wherein said catalyst is of the formula:

    [[Ph.sub.2 P(CH.sub.2).sub.m ].sub.y Si(CH.sub.3).sub.4-y ].sub.g Rh(CO)H

wherein m is 2-14, Ph is phenyl, y is 1 to 3 and g is 2 or
 3. 12. The process of claim 1 wherein said olefin is a terminal olefin.
 13. The process of claim 1 wherein said olefin is a mixture of butene-1 and cis- and trans-butene-2.
 14. A combined hydroformylation-aldolization process for converting a C_(n) olefin feed, said olefin being a terminal or internal olefin or mixture thereof, to a C_(2n+2) aldehyde comprising the steps of:(a) reacting said olefin with CO and H₂ at a temperature in the range of about 120° to 175° C. and a total pressure in the range of about 15 to 2000 psia in a reaction zone containing a liquid reaction mixture comprising a base aldol condensation catalyst and a homogeneous, non-charged hydroformylation catalyst complex of the formula:

    [[Ar.sub.2 P(CH.sub.2).sub.m ].sub.y SiR.sub.4-y ].sub.3 Rh(CO)H

wherein Ar is a substituted or unsubstituted C₆ to C₁₀ aromatic radical, R is an unsubstituted or monosubstituted C₁ to C₁₀ hydrocarbyl radical, m is 2 to 14, y is 1 to 4; said substituents on said aromatic radical, and on said hydrocarbyl radical being chemically unreactive with materials used in and the products of a hydroformylation reaction, and (b) withdrawing said liquid reaction mixture from said reaction zone and recovering said C_(2n+2) aldehyde.
 15. The process of claim 14 wherein said internal olefin reactant is in admixture with a hydrocarbon selected from the group consisting of terminal olefins, diolefins, C₁ -C₁₀ paraffinic hydrocarbons, aromatic hydrocarbons, or mixtures thereof.
 16. The process of claim 14 wherein said process is carried out in a continuous recycle flash off mode of operation wherein said withdrawn liquid reaction mixture is further heated under reduced pressure to continuously recover product aldehyde and recovered catalyst is recirculated back to said liquid reaction mixture. 